Full opinion text
MYRON L. GORDON, Senior District Judge. The appellants are fifteen defendants who have been convicted of various narcotics offenses. They raise a number of challenges to their convictions and sentences. Because we find no merit in the challenges to the convictions of the appellants, the convictions will be affirmed. However, we conclude that appellants James Velasquez and Julio Rodriguez are entitled to resen-tencing. I. BACKGROUND In January 1989, a grand jury returned a 101 count indictment against 27 defendants charging each of them with having conspired to distribute cocaine between March 1988 and January 1989 in violation of 21 U.S.C. § 846. In addition, the indictment charged certain of the defendants with distributing cocaine in violation of 21 U.S.C. § 841, using the telephone to facilitate the distribution of cocaine in violation of 21 U.S.C. § 843(b), and the enhanced offense of distributing cocaine within 1000 feet of a school in violation of 21 U.S.C. § 845a. Of the twenty-seven original defendants, fifteen ultimately went to trial (collectively, the “trial defendants”): Giovanni Saldarria-ga, Horacio Velasquez, Jose Castaneda, James Velasquez, Rolando Cándelo, Jaime Concha, Gloria Concha, Henry Cordoba, Elmer Velasquez, Hernán Nestor Bermudez, Adriana Sandoval, Julio Rodriquez, Marco Granada, Hector Granada and Renzo Soto. Three of the original twenty-seven defendants, Antonio Mojica, Julio Velasco and Diego Argaez waived their right to a jury trial and entered guilty pleas. Antonio Mo-jica pled guilty to distributing cocaine and the enhanced offense of distributing cocaine within 1000 feet of a school; Julio Velasco and Diego Argaez pled guilty to the conspiracy charge. The evidence used against the trial defendants was obtained through the use of a government informant, Henry Olave, and an undercover agent, Sabina Carlson. Through Mr. Olave and Ms. Carlson the government infiltrated a large scale cocaine distribution network in Chicago. The evidence presented at trial consisted of the testimony of Mr. Olave and Ms. Carlson, taped telephone and in-person conversations, photographs, telephone records and physical evidence such as 6V2 kilograms of cocaine, guns, pagers and mobile phones. On September 18,1989, the jury returned guilty verdicts against fourteen of the fifteen trial defendants on the conspiracy charge; Renzo Soto was acquitted of this charge. In addition, certain trial defendants were convicted of distributing cocaine, using the telephone to facilitate the distribution of cocaine and the enhanced offense of distributing cocaine within 1000 feet of a school. Renzo Soto and Adriana Sandoval have not appealed any of their convictions. Diego Argaez filed a notice of appeal with this court on September 26, 1991. However, because Mr. Argaez has failed to file a brief presenting his arguments to the court and has failed to respond to two orders issued by this court directing him to explain his failure to file a brief (orders of December 30, 1991, and March 4, 1992), his conviction and sentence will be summarily affirmed. The remaining thirteen trial defendants, along with Antonio Mojica and Julio Velasco, have each lodged challenges to their convictions or sentences, or both. Despite the large number of objections advanced by the defendant-appellants, not all of them justify (nor will receive) detailed analysis by this panel. II. SUFFICIENCY OF THE EVIDENCE Thirteen appellants jointly argue that the government failed to prove the existence of a single, ongoing conspiracy as charged in the indictment. (Appellants Mojica and Ve-lasco do not join in this argument.) Also, seven of the appellants separately argue that the government failed to establish their participation in the single conspiracy. We will first address the joint contention that the government failed to establish the existence of a single wholesale conspiracy to distribute cocaine. Next, we will address each of the seven appellants’ individual challenges. A. Joint Challenge ■In their joint brief, the appellants argue that there was a fatal variance between the government’s charge in the indictment — an ongoing single conspiracy — and its proof at trial — multiple, narrower conspiracies. That is, these appellants. argue that the government’s evidence failed to establish that they shared a “common goal” and maintain that the relationship among them amounted to nothing more than mere association. Moreover, the appellants contend that while some of them may have had knowledge that a number of their co-appellants were in the drug trade, any contact between the appellants was founded on legitimate business reasons. A claim of fatal variance “amounts to a challenge to the sufficiency of the evidence supporting the jury’s finding that each defendant was a member of the same conspiracy.” United States v. Townsend, 924 F.2d 1385, 1389 (7th Cir.1991). Determining the existence of a single conspiracy is a question of fact for the jury; thus, “the jury gets first crack at deciding ‘whether there is one conspiracy or several when the possibility of a variance appears.’ ” United States v. Paiz, 905 F.2d 1014, 1019 (7th Cir.1990), cert. denied, — U.S. -, 111 S.Ct. 2278, 114 L.Ed.2d 729 (1991) (quoting United States v. Percival, 756 F.2d 600, 609 (7th Cir.1985)). When evaluating a challenge to the sufficiency of the evidence, “[t]he test is whether, after viewing the evidence in the light most favorable to the government, ‘any rational trier of fact could have found the elements of the crime beyond a reasonable doubt.’ ” United States v. Aguilar, 948 F.2d 392, 395 (7th Cir.1991) (quoting Jackson v. Virginia, 443 U.S. 307, 319, 99 S.Ct. 2781, 2789, 61 L.Ed.2d 560 (1979) (emphasis in original). A material variance from an indictment charging a single conspiracy does not exist even if the evidence arguably established multiple conspiracies where a reasonable trier of fact could have found beyond a reasonable doubt the existence of a single conspiracy charged in the' indictment. Townsend, 924 F.2d at 1389 (citing United States v. Prince, 883 F.2d 953, 959 (11th Cir.1989)). The government is not required to demonstrate the existence of a formal agreement to conspire; it may rely upon “circumstantial evidence and reasonable inferences drawn therefrom concerning the relationship of the parties, their overt acts, and the totality of their conduct. ...” United States v. Sullivan, 903 F.2d 1093, 1098 (7th Cir.1990) (quoting United States v. Redwine, 715 F.2d 315, 320 (7th Cir.1983), cert. denied sub nom. Strong v. United States, 467 U.S. 1216, 104 S.Ct. 2661, 81 L.Ed.2d 367 (1984)). Where a jury may reasonably infer a single agreement among the defendants from the evidence of the drug transactions proffered by the government, the jury verdict must be upheld. Townsend, 924 F.2d at 1390. That is, “if the evidence indicates that a defendant must have known that his actions were benefitting a larger conspiracy, he may be said to have joined the conspiracy.” Townsend, 924 F.2d at 1390. “A single conspiracy exists ‘[i]f there is one overall agreement among the various parties to perform different functions in order to carry out the objectives of the conspiracy.’ ” Paiz, 905 F.2d at 1020 (quoting United States v. Sababu, 891 F.2d 1308, 1322 (7th Cir.1989)). On the other hand, “ ‘[Multiple] conspiracies exist when each of the conspirators’ agreements has its own end, and each constitutes an end in itself.’ ” Paiz, 905 F.2d at 1020 (quoting Sababu, 891 F.2d at 1322). A review of the record demonstrates that the evidence was more than sufficient to support the jury’s finding of a single conspiracy. The record establishes that the appellants enjoyed an ongoing cooperative relationship which facilitated the success of a common venture — a wholesale drug distribution network. The record is replete with evidence of the appellants’ cooperation and interrelations. There was evidence that the appellants regularly referred potential customers to one another. Also, the appellants had a detailed and accurate knowledge of the drug trafficking activities of one another, including such details as the dates and times of transactions, and the quality, quantity and prices of drugs that were available. Such evidence is highly probative of the existence of an agreement to carry out the objectives of the conspiracy. See United States v. Grier, 866 F.2d 908, 927 (7th Cir.1989) (knowledge of a codefendant’s drug dealing activities along with a close personal relationship are relevant to the existence of a single conspiracy). The record also includes evidence of the appellants’ reliance upon one another, rather than one source, to ensure the availability of a supply of cocaine for their customers. The appellants argue that the existence of multiple sources of cocaine, rather than a solitary source, contradicts the existence of a single conspiracy. However, the existence of a single conspiracy does not depend upon the number of component parts of the “organizational chart,” but rather depends upon an agreement to cooperate among all the component parts. See Townsend, 924 F.2d at 1391-92. Furthér, the record contains evidence of the appellants’ mutual trust and interest in achieving the goal of the conspiracy including a willingness to “front” cocaine to one another and to collect debts for one another. The government also presented evidence which established that the relationship among the appellants was ongoing and exclusive. The continuing nature of the appellants’ relationship was evidenced by the fact that the appellants each lived in the same small Colombian community where a number of the appellants owned businesses. (Jaime and Gloria Concha owned a jewelry store, as did Hector Granada, Nestor Bermudez owned a “knickknack” store, Horacio Velasquez owned an automobile repair garage, and Rolando Cándelo had a radio program on a local spanish-speaking radio station.) The appellants’ relationship was also marked by a high degree of exclusivity. Such exclusivity was evidence by the fact that the appellants refrained from dealing with non-Colombians and were reluctant to deal with individuals whom they did not know. Also, the appellants used a common code that was unique to their association insofar as it was comprised of terms commonly used in the jewelry business. For example, various appellants referred to a kilogram of cocaine as a “watch” or a “diamond” and a half kilogram as a “bracelet.” The use of a common code, especially a code comprised of terms not ordinarily used by drug dealers, supports the inference that the appellants conspired together. See Townsend, 924 F.2d at 1395, n. 5 (citing Grier, 866 F.2d at 922). Viewing this evidence in a light most favorable to the government, we believe that the evidence is sufficient to support the jury’s determination that the appellants engaged in an ongoing single conspiracy. B. Individual Challenges In their individual briefs, seven of the fifteen appellants separately argue that the evidence was insufficient to demonstrate his or her participation in the conspiracy. An essential element of a conspiracy is a “participatory link” between the conspiracy and the defendant. United States v. Navarez, 954 F.2d 1375, 1380-81 (7th Cir.1992). The government has met its burden with respect to this element when it presents sufficient evidence demonstrating that the “defendant knew of the conspiracy and that he [or she] intended to join and associate himself [or herself] with its criminal design and purpose.” Navarez, 954 F.2d at 1381 (quoting United States v. Auerbach, 913 F.2d 407, 415 (7th Cir.1990)). When evaluating a challenge to the sufficiency of the evidence to connect a particular appellant to a conspiracy, the test is “substantial evidence” rather than “slight evidence” or a “slight connection.” United States v. Durrive, 902 F.2d 1221, 1228 (7th Cir.1990). However, circumstantial evidence may support a conspiracy conviction. Navarez, 954 F.2d at 1381. We shall analyze the appellants’ individual challenges to the sufficiency of the evidence in the order in which the appellants are named in the case caption. 1. Jose Castaneda Mr. Castaneda contends that although a conspiracy may have existed, he had no knowledge of it or intent to join it. That is, Mr. Castaneda suggests that the evidence, at best, establishes only that he agreed to make a single delivery of cocaine to Socorro Granada, appellant Jaime Con-cha’s sister. According to the government, the evidence clearly established that Mr. Castaneda acted in concert with members of the conspiracy — namely, Gloria Concha, Jaime Concha and Marco Granada — to advance a common objective: the wholesale distribution of cocaine. In addition, the government contends that Mr. Castaneda possessed knowledge of the conspiracy and intended to join it. We believe that there was substantial evidence — both direct and circumstantial— in support of the government’s position. On April 21, 1988, Mr. Castaneda delivered a half kilogram of cocaine to Socorro Granada which was ultimately to be purchased by Mr. Olave, the confidential informant, and Ms. Carlson, the undercover agent. Prior to the delivery, Socorro Granada informed Mr. Olave and Ms. Carlson that while she typically worked with her brother Jaime Concha when she participated in cocaine deals, she was aware of Mr. Castaneda’s course of dealing and advised them that Mr. Castaneda, known to her as “El Tio,” was strictly business and would not tolerate her being late. When they arrived at the prearranged location, Socorro Granada told Mr. Olave and Ms. Carlson that Mr. Castaneda did not want to be seen by them. Ms. Granada’s statement suggests that Mr. Castaneda was aware that the sale did not end with Ms. Granada. In October 1988, Mr. Castaneda approached Mr. Olave while Mr. Olave was working on Mr. Castaneda’s car and suggested that Mr. Olave contact him if he had any customers interested in buying any cocaine. In addition, Mr. Castaneda was mentioned by Marco Granada, a co-conspirator, to Mr. Olave, as a possible source of cocaine and by the Conchas as someone who owed them money. When Mr. Castaneda was arrested, a stash box, portable phone and a pager were found in his possession. Thus, contrary to Mr. Castaneda’s assertion, the evidence, although largely circumstantial, strongly indicates that Mr. Castaneda’s involvement with the conspiracy went beyond an isolated sale of cocaine to Socorro Granada. In fact, the evidence indicates that Ms. Socorro (who admitted her involvement with the Conchas) and Mr. Castaneda had dealt with each other on previous occasions: she knew his course of dealing, and he was aware that she was going to resell the cocaine. The evidence also showed that Mr. Castaneda was interested in carrying out the objectives of the conspiracy: he offered to sell drugs to Mr. Olave and possessed tools of the trade including a pager which promotes accessibility and a stash box which is utilized for transporting large quantities of cocaine. More notably, the evidence demonstrates a link between Mr. Castaneda and other co-conspirators, namely, Marco Granada and the Conchas. Indeed, the evidence suggested that his relationship with the Con-chas involved a degree of trust insofar as the Conchas had fronted cocaine to him. Accordingly, viewing the direct and circumstantial evidence in a light most favorable to the government, we cannot say that there was insufficient evidence upon which a jury could reasonably infer that Mr. Castaneda was fully' aware of the existence of the conspiracy and intended to further its purpose. 2. James Velasquez James Velasquez was found guilty of conspiring to distribute cocaine and aiding and abetting the distribution of 250 grams of cocaine. Mr. Velasquez challenges his conspiracy and aiding and abetting convictions on a single ground: that the evidence failed to establish his knowledge and intent to participate in the conspiracy or to distribute the 250 grams of cocaine. That is, he contends that the evidence proffered by the government merely established that he was associated with members of the conspiracy through his familial ties with “most of the co-defendants” and that he was present at the scene of the crime. His attack, as to both convictions, is aimed primarily at the credibility of the government witnesses, namely, Ms. Carlson and Mr. Olave. . The government maintains that the record discloses that Mr. Velasquez, through his involvement in counter-surveillance, had knowledge of the general aims of the conspiracy and was an active participant therein. In , addition, the government asserts that the evidence also demonstrates that he knowingly and intentionally aided and abetted the distribution of a quarter kilogram of cocaine on June 21, 1988. Like the crime of conspiracy, the elements of aiding and abetting the distribution of cocaine include “association” and “participation”. United States v. Gonzalez, 933 F.2d 417, 433 (7th Cir.1991) (citing United States v. Valencia, 907 F.2d 671, 677 (7th Cir.1990)). To prove “association,” the government must establish that the defendant “either knowingly or intentionally aided and abetted....” Gonzalez, 933 F.2d at 444 (quoting Valencia, 907 F.2d at 680). “Participation” requires evidence to establish that the defendant engaged in some affirmative conduct to aid in the success of the venture; “a high level of activity need not be shown....” Gonzalez, 933 F.2d at 443 (quoting United States v. Beck, 615 F.2d 441, 448 (7th Cir.1980)). As a preliminary matter, Mr. Velasquez argues that the testimony of Mr. Olave and Ms. Carlson was not properly considered by the jury because such testimony was uncorroborated and contradicted by other evidence. To the extent that Mr. Velasquez’s argument amounts to a challenge to the credibility of the government's witnesses and the weight of their testimony, it is without merit. It is not the task of this appellate court to reconsider the evidence or assess the credibility of the witnesses. Paiz, 905 F.2d at 1021; United States v. Whaley, 830 F.2d 1469, 1472 (7th Cir.1987), cert. denied, 486 U.S. 1009, 108 S.Ct. 1738, 100 L.Ed.2d 202 (1988). Viewing the evidence in a light most favorable to government, we find that Mr. Velasquez’s characterization of his association with the members of the conspiracy is belied by the evidence. On June 21, 1988, Mr. Olave and Ms. Carlson went to a garage owned by Horacio Velasquez in order to purchase a quarter kilogram of cocaine from Jorge Suarez. Shortly after their arrival, Mr. Olave and Ms. Carlson left with Mr. Suarez in a van. Meanwhile, Mr. Velasquez was observed by members of the Drug Enforcement Agency (DEA) surveillance team behind the garage acting as a look-out. -As a result of his efforts, Mr. Velasquez spotted the DEA surveillance car that was following Mr. Suarez in the van. When Mr. Suarez returned to the garage with Mr. Olave and Ms. Carlson, Mr. Velasquez informed them that they had been followed and described the DEA vehicle. Further, Mr.'Velasquez informed them that he believed that appellant Marco Granada had brought the “heat” to the garage on a previous occasion when he had been followed in the same van. Because of Mr. Velasquez’s warning, Mr. Suarez recommended that the deal be completed at his apartment rather than at the garage. At Mr. Velasquez’s suggestion, they temporarily abandoned the van and used Mr. Suarez’s car to transport them to the new location. During the drive to Mr. Suarez’s apartment, Mr. Velasquez again acted as a lookout in the back seat of the car. When the group arrived at their destination, Mr. Velasquez remained outside the apartment for a short while to ensure that they had not been followed by the police. However, when Rudolfo Velasquez arrived at the apartment, he informed the group, including James Velasquez, that he had seen a police car nearby. At this point, Rudolfo Velasquez and James Velasquez were told that the “deal” would be rescheduled if they confirmed that police were nearby. Indeed, they did confirm the presence of the police, and the deal was ultimately rescheduled. Approximately one week later, Mr. Velasquez again was identified by a DEA surveillance team allegedly engaging, in “counter-surveillance” outside Mr. Suarez’s apartment building. This evidence contradicts Mr. Velasquez’s contention that he had no knowledge of the conspiracy and was merely acting as a look-out on one isolated occasion. His knowledge of Marco Granada’s drug dealings and previous involvement with the police at the same garage, his repeated role in counter-surveillance, Suarez’s statement to him that the deal would be rescheduled if the police were present, and his relationship with most of the co-defendants support the jury’s inference that Mr. Velasquez knew of the conspiracy and intended to join it. Although Mr. Velasquez accurately points out that participation in counter-surveillance, without more, is insufficient to establish one’s membership in the conspiracy, Mr. Velasquez’s involvement went beyond mere counter-surveillance. See United States v. Villegas, 911 F.2d 623 (11th Cir.1990), cert. denied, — U.S. -, 111 S.Ct. 1625, 113 L.Ed.2d 722 (1991). Mri Velasquez’s awareness of the purpose of the conspiracy is verified in the apprehension enunciated in his statement to Mr. Suarez, Ms. Carlson and Mr. Olave concerning the possibility that the van had been identified by the police and by the fact that he was present when Mr. Suarez notified everyone that the deal would be rescheduled if the police were nearby. In addition, Mr. Velasquez’s interest in the success of the overall operation is confirmed by the fact that he took steps to stop the drug transaction from going forward as-planned when he detected the presence of the police. The evidence also indicates that he acted as a look-out on more than one occasion. We believe that such evidence amply supports an inference that Mr. Velasquez was aware of the general aims of the conspiracy and agreed to act as a look-out in order to carry out the objectives of the conspiracy. Based upon this conclusion, and in view of the evidence, we find that a reasonable jury could also have found that Mr. Velasquez affirmatively aided the distribution of a quarter kilogram of cocaine on June 21, 1988, and properly found him guilty of aiding and abetting the distribution of cocaine. See Gonzalez, 933 F.2d at 443. 3. Rolando Cándelo Rolando Cándelo argues that the proof offered by the government showed nothing more than that he made one isolated sale to Mr. Olave and Ms. Carlson. On the other hand, the government characterizes Mr. Cándelo as an experienced member of the conspiracy whose interest went beyond the immediate sale. The evidence supports the government’s view. Mr. Cándelo, like Mr. Velasquez, asks this court to reject the testimony of the government’s witnesses on the ground that it misinterprets various statements that he made to the witnesses. As we have previously noted, it is not our task to reevaluate determinations of the weight of evidence or the credibility of witnesses. See Paiz, 905 F.2d at 1021. Thus, we decline to accept Mr. Candelo’s invitation and will proceed to determine whether the record contains sufficient evidence to support the jury’s verdict. The record reveals that Mr. Olave was first introduced to Mr. Cándelo in July 1988 by Giovanni Saldarriaga at Mr. Saldarria-ga’s record store. Mr. Olave testified that after the introductions Mr. Saldarriaga stated that Mr. Cándelo would “give [Mr. Olave] some work .... mechanic’s work as well as purchasing some dope.” In fact, “some work” was again offered to Mr. Olave later in July by Mr. Cándelo himself when Mr. Olave was working on Mr. Can-delo’s car. At this time, Mr. Cándelo offered to sell cocaine to Mr. Olave so that Mr. Olave could resell the narcotics to his customers. Consequently, the two exchanged pager numbers. Thereafter, Mr. Saldarriaga encouraged Mr. Olave to take Mr. Cándelo up on his offer when Mr. Saldarriaga was unable to provide Mr. Olave with any cocaine. On August 3, 1988, a sale of 250 grams of cocaine was perfected between Mr. Cándelo, Mr. Olave and Ms. Carlson. Mutuality of interest between Mr. Cánde-lo and Mr. Saldarriaga, an active member of the conspiracy, is evidenced by the fact that Mr. Saldarriaga took a number of steps to encourage a “business” relationship between Mr. Cándelo and Mr. Olave. In addition, Mr. Candelo’s knowledge of the drug ring’s goals and his desire to carry them out can be inferred from the fact that he shared information of his trade practices with Mr. Olave and gave him advice to guarantee the success of their operation. For instance, when Mr. Cándelo and Mr. Olave were planning the transaction, Mr. Cándelo advised Mr. Olave that someone other than Mr. Olave should pick up the cocaine personally to avoid any problems. Mr. Candelo’s participation in a recorded telephone conversation with Jaime Concha and Hector Granada in which Jaime Concha asked Mr. Granada how it went for him on his two-day trip to the Bahamas and Disney World and inquired as to collection matters supports a reasonable inference that Mr. Concha was aware of his activities. Furthermore, Mr. Olave testified that Mr. Concha was involved in transporting drugs from Florida. Thus, it is not unreasonable for the jury to have inferred that Mr. Concha’s inquiry regarding Mr. Granada’s two-day trip to Disney World, located in Florida, was actually an inquiry concerning drug trafficking. Based on all of this evidence and all reasonable inferences drawn therefrom, the jury had a sufficient basis to conclude beyond a reasonable doubt that Mr. Cánde-lo was a knowing participant, in the single cocaine distribution conspiracy. 4. Jaime Concha Jaime Concha attempts to trivialize the evidence offered against him by arguing that it shows no more than a buyer-seller relationship between him, as the seller, and various individuals, as buyers. We agree with the government that Mr. Concha oversimplifies the proof against him and his role in the conspiracy. It is true, as Mr. Concha asserts, that a “relationship of buyer-seller absent any prior or contemporaneous understanding beyond the mere sales agreement does not prove a conspiracy.” Townsend, 924 F.2d at 1394 (emphasis in original). However, we believe that' there was substantial evidence which confirmed that Mr. Concha’s interest transcended the individual sale. In addition to the fact that the evidence disclosed that Mr. Concha himself sold narcotics to Mr. Olave and to a number of the appellants (Hector Granada, Marco Granada, Horacio Velasquez and Henry Cordoba), the evidence also reveals that Mr. Concha referred Mr. Olave to other conspirators when his own supply was drained. For instance, the evidence discloses that on September 28, 1988, Mr. Concha referred Mr. Olave to Horacio Velasquez and Elmer Velasquez when he could not fulfill his offer to sell a kilogram of cocaine to Mr. Olave. Mr. Concha recommended Mr. Velasquez because he was aware that Mr. Velasquez had 500 grams to sell and also suggested that Marco Granada be contacted because he too “could make a fast deal.” This evidence suggests a common purpose, and it also illustrates that Mr. Concha was aware, in detail, of the drug dealings of the other conspirators. Mr. Concha’s significance to the drug ring and his awareness of its overall purpose is verified by the fact that he was often contacted by other conspirators during the course of their deals. Specifically, on September 9, 1988, when Henry Cordoba was having difficulty locating a kilogram of cocaine for Mr. Olave, he telephoned Mr. Concha. Having failed to locate the desired cocaine, Hector Granada, Henry Cordoba and Mr. Olave tried again on September 13, 1988. A call was again made to Mr. Concha, this time by Hector Granada, in which Mr. Granada informed Mr. Concha of the time and location of the transaction. The evidence offered by the government also indicates that mutual trust existed between Mr. Concha and the other appellants. When Mr. Olave purchased drugs from Horacio Velasquez on July 27, 1988, he was informed that the money should be given to Mr. Concha. Similarly, when Elmer Velasquez sold a quarter kilogram to Mr. Olave, he directed Mr. Olave to drop off the money at Hector Granada’s house, where he was at the time, or at Mr. Concha’s house. Use of Mr. Concha’s house or his jewelry store as a “drop-off” site for drug payments .cogently illustrates that Mr. Concha was trusted and belies Mr. Concha’s assertion that his interest did not go beyond his own individual sale agreements. Furthermore, the fact that Mr. Concha utilized Horacio Velasquez’s garage and Hector Granada’s jewelry store as locations for his transactions illustrates that the trust was mutual. A desire to further the purposes of the conspiracy is evident from the fact that Mr. Concha fronted cocaine to Mr. Castaneda and Diego Argaez and that he in turn was fronted cocaine by Julio Velasco. Mr. Con-cha’s awareness of the purposes underlying the conspiracy is validated in the frequency with which members of the conspiracy discussed drug activities and actually engaged in the sale of drugs in the Con-cha’s jewelry store. In addition, his knowledge and use of the unique code comprised of jewelry terminology supports an inference that he was a member in the exclusive drug ring. In view of this abundant evidence, we are confident that a reasonable jury could properly find that Mr. Concha was a knowing and integral member of the single conspiracy. 5. Hernán Nestor Bermudez Hernán Nestor Bermudez was convicted of participating in the conspiracy and of one count of attempted distribution and one count of completed distribution of cocaine. He contends that the evidence was insufficient as to each of these convictions. We disagree. Although purporting to challenge all three of his convictions, Mr. Bermudez only focuses on his conspiracy conviction in his brief. We will follow his lead. The evidence reveals that on September 27, 1988, Mr. Bermudez, also known as “El Negro,” attempted to deliver a half kilogram of cocaine to Julio Velasco who had arranged to sell the drugs to Mr. Olave for $9,500. Prior to Mr. Bermudez’s arrival at the prearranged location, Mr. Velasco explained, in detail, how he and “El Negro” handled the cocaine. Specifically, he explained to Mr. Olave their weighing and packaging procedure and informed him that payment could be made to him or to Mr. Bermudez, it was “the same thing.” When Ms. Carlson approached Mr. Ber-mudez to obtain the cocaine, the latter told her not to talk to him but to keep walking because he had observed police officers nearby. In fact, Mr. Bermudez’s apprehension concerning the presence of the police officers caused him ultimately to abort the deal. The next day, Giovanni Saldarriaga, who had not directly participated in the deal, explained to Mr. Olave that Mr. Ber-mudez had scratched the deal because he had been fearful of the police. After meeting with Mr. Bermudez in his store on September 29, 1988, Mr. Velasco apprised Mr. Olave that approximately 850 grams of cocaine were available for sale and that the supply had been moved to Mr. Bermudez’s house. Mr. Velasco later advised Mr. Olave that Mr. Bermudez had promised to deliver approximately 450 grams of cocaine to them. That evening, Adriana Sandoval, Mr. Bermudez’s wife, delivered 400 grams of cocaine to Mr. Olave. The above series of events illustrates that Mr. Bermudez had knowledge of and agreed to participate in the wholesale cocaine distribution conspiracy. Mr. Velas-co’s statements to Mr. Olave regarding payment and the method of operation between himself and Mr. Bermudez evinces an ongoing relationship between Mr. Velas-co, a co-conspirator, and Mr. Bermudez. Moreover, Mr. Velasco’s statement that it was immaterial who received the payment supports an inference that their relationship entailed commonality of purpose and trust. Mr. Bermudez’s knowledge of the overall goal of the conspiracy and his stake in the outcome was demonstrated by his conduct on September 28, 1988 when he detected the presence of the police. Notwithstanding the aborted deal on September 28,1988, Mr. Bermudez was ready and willing to try again the next day. Moreover, it is apparent that Mr. Bermudez was linked to Mr. Saldarriaga, a faithful participant in the conspiracy, insofar as Mr. Saldarriaga had detailed knowledge of the aborted transaction within a short time of its occurrence. Thus, we conclude that the jury’s determination that Mr. Bermudez knowingly and intentionally participated in the conspiracy was not improper. We are also persuaded that the evidence was sufficient to demonstrate that Mr. Bermudez directly participated in the attempted distribution on September 28, 1988, and in the completed distribution on September 29, 1988. 6. Gloria Concha The government argued that, like her husband Jaime Concha, Gloria Concha was integral to the wholesale drug distribution conspiracy. Ms. Concha challenges the sufficiency of the evidence as to her convictions for conspiring to distribute cocaine, aiding and abetting the distribution of cocaine, and use of the telephone to facilitate the distribution of cocaine. She insists that the record shows only that she was fearful of her husband’s activities and was merely casually associated with the conspirators through her husband. The record contradicts her assertion as to each of the convictions. Ms. Concha initially asks this court to reverse her conspiracy conviction on the ground that the evidence against her was wholly circumstantial. The existence of direct evidence is not essential to prove one’s membership in a conspiracy where there is circumstantial evidence which supports, beyond a reasonable doubt, an inference that an individual agreed to participate in the conspiracy. United States v. Duarte, 950 F.2d 1255, 1259 (7th Cir.1991). Here, the evidence solidly supports such an inference. It is undisputed that Ms. Concha was linked with essential members of the drug conspiracy and that she had knowledge of the overall purpose of the conspiracy. In fact, in her brief, Ms. Concha readily admits that she had knowledge of her husband’s narcotics activities and those of his family and friends. Thus, what is at issue is Ms. Concha’s intent to participate in the conspiracy. Mr. Olave testified that in April 1988, Ms. Concha instigated a meeting among herself, her husband and Mr. Olave in which she and her husband discussed with Mr. Olave various “safe routes” to and from Florida for the purpose of transporting drugs. According to Mr. Olave, Ms. Concha and her husband also questioned him about his previous participation in the drug trading business. Her role in instigating such a meeting and the breadth of her knowledge regarding the drug trading operation substantiate the government’s contention that Ms. Concha intentionally and voluntarily participated in the conspiracy- Ms. Concha’s personal involvement in transactions with Mr. Olave and with members of the conspiracy also supports the government’s assertion that Ms. Concha personally and intentionally participated in the successful operation of the conspiracy. For instance, after Mr. Olave’s first transaction with Jaime Concha, Mr. Olave had a telephone conversation with Ms. Concha in which they discussed a second purchase of one kilogram of cocaine. During the conversation, Ms. Concha asked Mr. Olave to come to her house so that they could discuss the future transaction in detail and she urged him not to discuss the matter any further over the telephone. Mr. Olave testified that he had additional telephone conversations with Ms, Concha concerning the planned drug deal during August 1988. Specifically, on August 22, 1988, when Mr. Olave called the Concha’s jewelry store to obtain information regarding the impending drug deal, Ms. Concha encouraged Mr. Olave to come over to the jewelry store. When Mr. Olave spoke to Jaime Concha, he too encouraged Mr. Olave to come to the store and informed him that he had the cocaine. When he arrived at the store Jaime Concha had already left. Nevertheless, Ms. Concha instructed Mr. Olave that he was supposed to inform Diego Argaez, who was also present in the store, that he had arrived with the money. After Mr. Olave spoke with Diego Argaez, Ms. Concha inquired as to' their conversation and Mr. Olave informed her that he was to give the money for the cocaine to her husband. Contrary to Ms. Concha’s characterization of herself as a fearful and innocent wife, the above series of events indicates that she voluntarily participated in the activities of the conspiracy. The fact that Ms. Concha was left alone by her husband to await Mr. Olave’s arrival tends to support an inference that she was a trusted and willing member of the conspiracy. Not only did Ms. Concha actively seek out information regarding the drug transactions, but she facilitated the completion of the drug deal by encouraging Mr. Olave to come to the store so that the deal could be finalized with Diego Argaez. Ms. Con-cha’s involvement in planning “safe routes” to and from Florida for the purpose of transporting cocaine demonstrates that she had a stake in maintaining the successful operation of the conspiracy. Accordingly, we believe that the evidence as a whole amply supports an inference that Ms. Concha was a knowing and intentional participant in the conspiracy. Furthermore, the evidence adequately established that through her role in the August 22, 1988 transaction, Ms. Concha affirmatively helped in the success of the transaction such that the aiding and abetting conviction was proper. See Gonzalez, 933 F.2d at 443-44. Finally, Ms. Concha argues that the telephone call between herself and Mr. Olave on August 22, 1988, could not have facilitated any narcotics offense because her role was limited to answering the telephone. A telephone call “facilitates” the commission of a narcotics offense within the meaning of 21 U.S.C. § 843(b) if it “comes within the common meaning of facilitate — ‘to make easier’ or less difficult, or to assist or aid.” United States v. Phillips, 664 F.2d 971, 1032 (5th Cir.1981), cert. denied sub nom. Meinster v. United States, 457 U.S. 1136; 102 S.Ct. 2965, 73 L.Ed.2d 1354 (1982). Contrary to Ms. Concha’s assertions, her participation in the conversation with Mr. Olave on August 22, 1988 went beyond merely answering the telephone and handing it to her husband. Ms. Concha, knowing of the ensuing drug deal' with Mr. Olave, affirmatively encouraged Mr. Olave to come over to the store where Mr. Ar-gaez, the supplier, was waiting to make additional arrangements in connection with the deal. Thus, the jury could reasonably find that the August 22, 1988, call facilitated the sale by making the sale easier. 7. Julio Rodriquez Julio Rodriquez argues that the evidence demonstrates that he was attempting to swindle the -conspirators, not to join them. However, Mr. Rodriquez fails to point to any probative evidence which supports his theory. Instead, we find that the record provides sufficient evidence for the jury’s determination that Mr. Rodriquez knowingly and intentionally joined the conspiracy. The evidence shows that in September 1988, Mr. Rodriquez was directly involved in facilitating a half kilogram cocaine deal between Julio Velasco and Mr. Olave. On September 27, 1988, Mr. Velasco agreed to sell 500 grams of cocaine to Mr. Olave but when the deal culminated he was only able to deliver 307 grams. Nevertheless, Mr. Velasco promised, to provide the remaining grams to Mr. Olave the following morning. In an effort to complete the half kilogram deal with Mr. Olave, Mr. Velasco contacted Julio Rodriquez. Mr. Velasco, his brother Diego Argaez, and Mr. Rodriquez had participated in an earlier transaction which involved the sale of one kilogram of cocaine to the “Ecuadorian,” a customer of Mr. Rodriquez. Mr. Olave testified that Mr. Velasco and Mr. Argaez did not know the Ecuadorian, but they agreed to go through with the transaction because of their familiarity with Mr. Rodriquez. In fact, the evidence shows that Mr. Velasco and Mr. Argaez actually fronted the co-; caine to Mr. Rodriquez so that he could sell it to the Ecuadorian. Such evidence indicates the existence of a level of trust between these appellants. In addition, Mr. Rodriquez’s involvement in a transaction with Mr. Velasco, a committed member of the conspiracy, is evidence of an agreement on Mr. Rodriquez’s part to provide customers to the single conspiracy and thus facilitate its overall purpose. Although Mr. Velasco and his brother Diego Argaez satisfied their end of the bargain by providing the kilogram of cocaine to Mr. Rodriquez, the Ecuadorian still owed Mr. Velasco and Mr. Argaez money for the cocaine at the time of the deal between Mr. Velasco and Mr. Olave. Hence, Mr. Velasco hoped to obtain the grams of cocaine that he owed to Mr. Olave by reclaiming the cocaine that he had delivered to the Ecuadorian. Contrary to Mr. Rodriquez’s assertion that he and the Ecuadorian were attempting to cheat the conspirators, the evidence firmly supports an inference that he took steps to help Mr. Velasco reclaim the cocaine from the Ecuadorian. His cooperation in this regard is illustrated by the fact that he gave the Ecuadorian’s address and place of work to Mr. Velasco when Mr. Velasco expressed his intention to reclaim the cocaine. Mr. Rodriquez contends that he cooperated only because he was threatened with bodily force. However, Mr. Rodriquez did not testify at trial, and the record does not otherwise substantiate such a claim. To the extent that he mounts a challenge to the weight given to the evidence by the jury, such a challenge exceeds the scope of our review. See Paiz, 905 F.2d at 1021. We believe that Mr. Rodriquez’s assistance supports a reasonable inference that he had a stake in the successful operation of the conspiracy. Moreover, his assistance reasonably supports an inference that Mr. Rodriquez believed that the benefits that he derived from the operation were dependent upon the success of the entire venture. See United States v. Cerro, 775 F.2d 908, 911 (7th Cir.1985). At the same time, this evidence negates Mr. Rodriquez’s claim that he attempted to cheat the conspiracy. Circumstantial evidence also supports the jury’s finding that Mr. Rodriquez knowingly and intentionally participated in the conspiracy. Mr. Rodriquez’s involvement with other members of the conspiracy may be inferred from Mr. Velasco’s statement to Mr. Rodriquez that he was going to inform the “rest of the guys” of the problems that Mr. Velasco was having with Mr. Rodriquez’s customer. At trial, Mr. Olave testified that “the rest of the guys” referred to the other people with whom Mr. Rodriquez dealt. To the extent that Mr. Velasco is a core conspirator, it is a fair inference that these people included other members of the conspiracy. Accordingly we believe that Mr. Rodriquez’s association with notorious members of the conspiracy, his deal with Mr. Velasco and his willingness to assist Mr. Velasco in his efforts to reclaim cocaine from one of his own customers, the Ecuadorian, reasonably support an inference that Mr. Rodriquez actively participated in the conspiracy. III. SENTENCING CHALLENGES A. Joint Challenge The appellants jointly claim that the trial court committed reversible error by failing to give a tendered jury instruction concerning the determination of the amount of narcotics for which each appellant should be held accountable. Specifically, Judge Marovich refused to give the following tendered instruction: If you find any defendant guilty of conspiracy, you must determine from the evidence the quantity of cocaine distributed as a result of the defendant’s conduct or the conduct of co-conspirators in furtherance of the conspiracy that was known to the defendant or was reasonably foreseeable. The appellants contend that this instruction was required because the determination of the scope of the agreement and the amount of narcotics for which a given defendant is responsible are factual issues which .must be determined by the jury. However, the appellants do not dispute that such issues are relevant only to sentencing. It is firmly established that “[i]n the federal system, facts germane only to sentencing are resolved by the judge, not the jury.” United States v. Smith, 938 F.2d 69, 70 (7th Cir.) cert. denied, — U.S. -, 112 S.Ct. 254, 116 L.Ed.2d 208 (1991); See also United States v. Savage, 891 F.2d 145, 151 (7th Cir.1989) (not improper for district court to deny the defendant’s request for a jury determination of the scope of the conspiracy because facts relevant only to sentencing are determined by the judge). Furthermore, the appellants have not cited any authority in support of their argument that a district court is required to - provide a jury with a proffered jury instruction on the issue of the scope of the conspiracy. Hence, the district court’s decision to preclude a jury determination on accountability and the scope of the conspiracy was entirely proper. As an additional matter, the appellants jointly claim that the trial court “used improper standards of foreseeability in determining ‘relevant conduct’ under the Sentencing Guidelines.” This argument must be distinguished from the argument raised by a number of appellants individually that the Guidelines were incorrectly applied; the propriety of the trial judge’s application of the Guidelines will be addressed in the following section of this decision. The appellants’ claim that the trial judge employed an inappropriate standard under the Guidelines is not substantiated by anything in the record. The record shows that at the sentencing hearing of each of the appellants (except for that of Antonio Mojica, who was not found guilty of the conspiracy charge) the district judge cited our decision in Savage, 891 F.2d 145, as the applicable law on “relevant conduct” and foreseeability for sentencing purposes in narcotic conspiracy cases. On a number of occasions the district judge actually read into the record pertinent portions of Savage, including the following passage: The amount of narcotics considered in sentencing for conspiracy includes not only the amounts involved in the transactions that were known to the defendant but also those that were reasonably foreseeable, reflecting the fact that each conspirator is responsible for acts and offenses of each one of his conspirators committed in furtherance of the conspiracy. The sentence should be imposed on the basis of the defendant’s conduct or on the conduct of the conspiracy that was known to the defendant or was reasonably foreseeable. Savage, 891 F.2d at 151; Sentencing Guidelines § 2D1.4. We believe that this is an accurate statement of the standard of foreseeability to be applied by the district judge in determining relevant conduct when sentencing members of a narcotics conspiracy. See also United States v. Edwards, 945 F.2d 1387, 1394 (7th Cir.1991), cert. denied sub nom. Martin v. United States, — U.S. -, 112 S.Ct. 1590, 118 L.Ed.2d 308 (1992); United States v. Guerrero, 894 F.2d 261, 267 (7th Cir.1990); Sentencing Guidelines §§ 1B1.3(a), 2D1.1 and 2D1.4. Accordingly, we reject the appellants’ joint contention that the district court employed an incorrect standard of foreseeability under the Sentencing Guidelines. B. Individual Challenges Ten of the appellants individually challenge the district court’s application of the Sentencing Guidelines to their convictions. (Antonio Mojica, Henry Cordoba, Marco Granada, Hector Granada, and Julio Velasquez do not appeal their sentences.) Each of the ten claims that the district court incorrectly determined his or her base offense level by miscalculating the amount of drugs for which he or she was responsible. It is undisputed that the Guidelines apply to each of the sentencings in this case insofar as the conspiracy with which each of the appellants was charged began in 1988, after the effective date of the Guidelines. Moreover, all of the appellants were sentenced after November 1, 1989, the date on which certain amendments to the Guidelines took effect. The essence of the sentencing challenge launched by each of the ten appellants concerns the proper application of the Guidelines in determining the base offense level assigned by the district judge to each appellant. The base offense level corresponds with the quantity of drugs involved in the offense. See Sentencing Guidelines § 2D1.1. In calculating the base offense level, and thus, the quantity of drugs for which a given appellant is to be held accountable, the Guidelines require that the district judge determine the “relevant conduct” of the defendant which is defined under the Guidelines as “all acts and omissions committed or aided and abetted by the defendant, or for which the defendant would be otherwise accountable, ... that were in furtherance of that offense.” Sentencing Guidelines § lB1.3(a) (emphasis added). Application Note 1 to Guideline § lB1.3(a) clarifies the breadth of the “relevant conduct” to be considered by the sentencing judge and provides (with emphasis added): In the case of criminal activity undertaken in concert with others, whether or not charged as a conspiracy, the conduct for which the defendant “would be otherwise accountable” also includes conduct of others in furtherance of the execution of the jointly undertaken criminal activity that was reasonably foreseeable by the defendant.... Where it is established that the conduct was neither within the scope of the defendant’s agreement, nor was reasonably foreseeable in connection with the criminal activity the defendant agreed to jointly undertake, such conduct is not included in establishing the defendant’s offense level under this guideline. In other words, in calculating a defendant’s base offense level, a drug conspirator shall be held accountable “for all drug transactions that he was aware of or that he should have reasonably foreseen." Edwards, 945 F.2d at 1394 (quoting Guerrero, 894 F.2d at 267). An important consideration in determining what is reasonably foreseeable to a given defendant is the level of commitment demonstrated by that defendant. In assessing foreseeability, we have held that [Reasonable foreseeability means more than subjective awareness on the part of the individual defendants.... Instead, conduct of co-conspirators—even past conduct—can be considered “reasonably foreseeable” to a particular defendant if that defendant has demonstrated a substantial degree of commitment to the conspiracy’s objectives, either through his words or conduct. Edwards, 945 F.2d at 1393-94. In the present action, the ten appellants who individually challenge their sentences were not sentenced on the basis of the entire amount of drugs that flowed through the drug network. Rather, they were sentenced on the basis of the total amount of drugs that were sold by a member of the conspiracy to one of the government agents over a six month period (April 1988 through October 1988). This amount totalled 6.5 kilograms of cocaine. As to each of these appellants, the trial judge found that he or she could reasonably have foreseen that the conspiracy would involve the distribution of 6.5 kilograms of cocaine. Based on this finding, the district judge assigned a base offense level to the appellants that corresponded with the distribution of 6.5 kilograms of cocaine. Notably, the base offense level that was ultimately assigned to each of these appellants is triggered by a finding that the conspiracy involved five or more kilograms of cocaine. See Sentencing Guideline § 2Dl.l(c). Consequently, in order to affirm an appellant's sentence, we need only find that the appellant could reasonably foresee that the conspiracy that'he or she joined involved five or more kilograms of cocaine. The government bears the burden of proving the quantity of drugs that was reasonably foreseeable to a particular defendant by a preponderance of the evidence. United States v. Ross, 905 F.2d 1050, 1054 (7th Cir.), cert. denied, 498 U.S. 863, 111 S.Ct. 172, 112 L.Ed.2d 136 (1990). A district judge’s finding that the government has met its burden is a finding of fact which we will reverse only if it is found to be clearly erroneous. See United States v. White, 903 F.2d 457, 460 (7th Cir.1990). “A finding of fact is clearly erroneous only if, after reviewing the entire evidence, we are left ‘with the definite and firm conviction that a mistake has been committed.’ ” United States v. Herrera, 878 F.2d 997, 1000 (7th Cir.1989) (quoting Anderson v. City of Bessemer City, 470 U.S. 564, 573, 105 S.Ct. 1504, 1511, 84 L.Ed.2d 518 (1985)). Moreover, we are obliged to give due deference to a district court’s application of the Guidelines to the facts. Herrera, 878 F.2d at 1000; 18 U.S.C. § 3742(e). We now turn to the propriety of the base offense level for each of the ten appellants who have contested their sentences on this basis. 1. Giovanni Saldarriaga Giovanni Saldarriaga argues that he is entitled to “resentencing as a matter of law” solely on the ground that the judge’s statement of reasons underlying the sentence imposed upon him was “conclusory.” Mr. Saldarriaga relies on our recent decision in Edwards, 945 F.2d 1387, to support his contention that a failure to enunciate specific reasons underlying the sentence, without more, constitutes reversible error. Mr. Saldarriaga misinterprets our ruling in Edwards. Although our decision in Edwards stresses the need for sentencing judges to make particularized findings in sentencing defendants under the Guidelines, that decision does not stand for the proposition that the judge’s failure to go beyond a generic statement of reasons entitles a defendant to resentencing as a matter of law. Indeed, in Edwards, we expressly stated that in the absence of such individualized findings, we are required to determine, on a “defendant-by-defendant” basis whether a given defendant “has offered meritorious arguments for remanding” the case for resentencing. Edwards, 945 F.2d at 1400. Moreover, a defendant is not entitled to a remand for resentencing on this basis where, as here, he fails to raise an objection to the district court’s explanation at the time of sentencing. United States v. Caicedo, 937 F.2d 1227, 1236 (7th Cir.1991). Mr. Saldarriaga’s failure to object to the explanation given by the judge at sentencing therefore waives this argument. Notwithstanding Mr. Saldarriaga’s waiver of this argument, the record reveals that the district judge did articulate particularized reasons for Mr. Saldarriaga’s sentence. Judge Marovich first quoted the standard of foreseeability enunciated by this court in Savage. He then made the following findings: (1) that Mr. Saldarriaga was the “initial player” in the conspiracy insofar as it was he who introduced Mr. Olave to Mr. Concha; (2) that Mr. Saldarri-aga was personally involved in the sale of 965 grams of cocaine; (3) that the evidence at trial connected him with eight other conspirators; and (4) that the evidence presented at trial demonstrated that he was more than casual acquaintances with each of the eight conspirators. The trial judge’s statement of reasons made it clear that he had considered the evidence of Mr. Saldarriaga’s agreement to join a conspiracy of the scope alleged by the government. See Edwards, 945 F.2d at 1399. Thus, Judge Marovich offered more than a boilerplate explanation as a basis for his conclusion that Mr. Saldarria-ga could reasonably foresee the distribution of 6.5 kilograms of cocaine. Mr. Saldarriaga does not challenge the express findings made by the district judge nor has he advanced any basis for our concluding that the conspiracy that he joined was a narrower one or that the 6.5 kilograms of cocaine was not reasonably foreseeable to him. Accordingly, we decline to disturb the district court’s finding that Mr. Saldarriaga could reasonably have foreseen the distribution of 6.5 kilograms of cocaine through the conspiracy. 2. Horacio Velasquez Horacio Velasquez makes the same argument for resentencing as advanced by Mr. Saldarriaga. We reject it for similar reasons. Like Mr. Saldarriaga, Mr. Velasquez failed to object to the explanation for imposing the sentence articulated by the district judge at the sentencing hearing. Hence, Mr. Velasquez has also waived this argument. Caicedo, 937 F.2d at 1236. Further, despite Mr. Velasquez’s contention, the record discloses that the district judge did make particularized findings with respect to Mr. Velasquez’s role in the conspiracy. He found that (1) Mr. Velasquez directly participated in two transactions which involved a total of “about 1200, 1250 grams of cocaine”; (2) one of the deliveries with which he was involved was “amongst the biggest amounts that were involved and represents about 20 percent of the total that was involved in the conspiracy”; and (3) Mr. Velasquez had more than a casual relationship with at least eight conspirators, including such central figures as Diego Argaez, Marco Granada, and Jaime Concha. The district judge’s statements illustrate that he had considered the evidence of Mr. Velasquez’s agreement to join the conspiracy of the scope alleged by the government. Hence, notwithstanding his waiver of this argument, we find no support in the record for Mr. Velasquez’s assertion that the district judge failed to articulate the reasons underlying the sentence imposed upon him. Like Mr. Saldarriaga, Mr. Velasquez does not challenge the district judge’s findings themselves, nor does he articulate a basis for holding that he joined a narrower conspiracy. Therefore, we decline to vacate the district judge’s determination that Mr. Velasquez had an extensive role in the conspiracy such that he could reasonably have foreseen the distribution of 6.5 kilograms of cocaine. 3. Jose Castaneda Jose Castaneda claims that resentencing is required because the evidence does not show an agreement to distribute cocaine beyond his one proved sale of 499 grams. The record reveals that the district judge, after quoting the standard for relevant conduct and foreseeability under Savage, offered the following explanation for sentencing Mr. Castaneda on the basis of 6.5 kilograms of cocaine: Based on the evidence that was adduced at trial, it .. is the judgment of the Court that Mr. Castaneda also could have reasonably foreseen the amount of cocaine that was involved in the conspiracy and, therefore, he is to be charged with that amount_ Although the district judge offered a generic explanation for assigning the base offense level of 6,5 kilograms to Mr. Castaneda, we are obligated to assess whether Mr. Castaneda offers a meritorious argument for remanding his case for resentenc-ing. Edwards, 945 F.2d at 1399-1400. Mr. Castaneda identifies no evidence to substantiate his claim that the district judge erroneously found that the distribution of 6.5 kilograms of cocaine was reasonably foreseeable to him. On the contrary, the evidence discloses that Mr. Castaneda participated in the conspiracy throughout the entire six month period charged in the indictment. He was directly involved in a one-half kilogram deal with Mr. Olave and Socorro Granada in April 1988. During this transaction, Socorro Granada informed Mr. Olave that she had dealt with Mr. Castaneda, or “El Tio” (as he was also called) on prior occasions. Also, Mr. Olave testified that in October 1988, Mr. Castaneda offered to supply Mr. Olave and his customers with drugs if he or his customers had such a need. A taped conversation between Jaime