This document discusses measures of central tendency including mode, harmonic mean, and geometric mean. It provides definitions and formulas for calculating each measure. For mode, it explains that it is the value with the highest frequency and can be determined using grouping tables or the formula Mode = 3Median - 2Mean. It also provides examples of calculating mode from individual observations and discrete/continuous data series. For harmonic and geometric means, it similarly gives definitions and examples of calculating each from discrete and continuous data series using common formulas.