This is a 12-week clinical trial in participants with mixed hyperlipidemia to study the effects of MK-0524B on lipids.The primary hypothesis is that MK-0524B (dosed as MK-0524A coadministered with simvastatin) will be superior to atorvastatin on decreasing the low denisity lipoprotein cholesterol (LDL-C)/high-density lipoprotein cholesterol (HDL-C) ratio for the following dose comparisons: 2g/20 mg MK-0524B versus 10 mg atorvastatin, 2g/40 mg MK-0524B versus 20 mg atorvastatin, 2g/40 mg MK-0524B versus 40 mg atorvastatin, and 2g/40 mg MK-0524B versus 80 mg atorvastatin.