Standard Deviation

Standard Deviation can be thought of as “the average distance each data point is from the average of the entire data set”. If you add the squared distance each point is from the average value and divide by the number of points in the population, or 1 minus the number of data points for a sample, then take the square root of the answer, you will find your Standard Deviation.

The distances are squared to eliminate any negative values. It is the most common measure of the variability of a set of data.