Measure Of Dispersion (Cont.)

 3.    The standard deviation

A deviation is the difference between an individual value in a set of data and the mean for the data.

Standard Deviation averages the square of the distance that each piece of data is from the mean.

The smaller the standard deviation, the more compact the data set.

                                                          Standard Deviation – Population

                                                           

                                                                 Standard Deviation – Sample