## Variance VS Coefficient of variation [General Sta­tis­tics]

Hello!

In the formulas for calculating the number of subjects on logarithmic scale, should we use the variance or the coefficient of variation? In Chow's paper (On Sample Size Calculation in Bioequivalence Trials, 2001) we see the variance in the formula on log-sclae while in his book (Design and Analysis of Bioavailability and Bioequivalence Studies, 2009) we see th coefficient of variation in the formula on log-scale.