Figure 1. Theoretical concentrations for three subjects (#1, #2, #3) given acetaminophen rectally are shown. Each thin line represents values for an individual subject; the thick line is the average of the values for the three individuals. If the curves peaked simultaneously, the mean of the peak concentrations would equal the peak of the mean concentrations. However, the peak of the average curve is less than the average of the peak of each of the individual curves, a result of each curve peaking at a different time.