Question

What is the significance of standard deviation?

Answer 1

The standard deviation is a commonly used statistic, but it doesn’t often get the attention it deserves. Although the mean and median are out there in common sight in the everyday media, you rarely see them accompanied by any measure of how diverse that data set was, and so you are getting only part of the story. In fact, you could be missing the most interesting part of the story.

Without standard deviation, you can’t get a handle on whether the data are close to the average or whether the data are spread out over a wide range.