This section describes the computational formulas for the estimates, confidence limits, and tests for each analysis in the TTEST procedure. The first subsection defines some common notation. The second subsection discusses the distinction between arithmetic and geometric means. The third subsection explains the concept of the coefficient of variation. The following four subsections address the four supported designs (one-sample, paired, two-independent-sample, and AB/BA crossover). The content in each of those subsections is divided into separate discussions according to different values of the DIST= and TEST= options in the PROC TTEST statement. The last subsection describes TOST equivalence analyses.