What is the importance of the standard deviation?

Answer 1

It allows you to understand, or comprehend the average fluctuation to the

average. example: the average height for adult men in the United States is about

70", with a standard deviation of around 3". This means that most men (about

68%, assuming a normal distribution) have a height within 3" of the mean (67"-

73"), one standard deviation, and almost all men (about 95%) have a height

within 6" of the mean (64"-76"), two standard deviations.

In summation standard deviation allows us to see the 'average' as a whole.

Answer 2

It helps understand the variability in a set of data. Specifically it helps you to see how close values in your data set are to the mean.