(a) The normal monthly precipitation (in inches) for August is listed for 20 different U.S. cities. Find the mean of the data.

(b) Calculate the standard deviation for the data

Solution: (a) The mean is computed as

(b) By definition, the standard deviation is computed as


Stats Solution Summary

When using descriptive statistics, the mean is used as a measure of center, and the standard deviation is used as a measure of dispersion, which provide a rough view of the distributional properties of the population from which the sample was drawn.