Whether a district court can infer that unseized methamphetamine has similar purity to seized methamphetamine. If so, what specific evidence must support such an inference, i.e., the source of the drugs, the pricing of the drugs, and/or the purity of other drugs from the same supplier at the same or a comparable price. Under any standard, the District Court, the Government, and the PSR failed to offer sufficient evidence to support such an assumption by a preponderance of the evidence.

Whether a district court can infer that unseized methamphetamine has similar purity to seized methamphetamine and what specific evidence must support such an inference