Learn by Doing – Comparing Probability Distributions #2
Keeping in mind that the mean describes where a histogram is centered, and the standard deviation describes spread by reporting the typical distance of values from their mean, match the random variable in each of the histograms here to the correct combination of mean and standard deviation.
http://phhp-faculty-cantrell.sites.medinfo.ufl.edu/files/2013/02/qzLBD_08003.swf
This document is linked from Discrete Random Variables.