Prerequisites: Reviewing Data Collection and Analysis

Standard Deviation

The standard deviation of a set of values is the measure of the dispersion of the data from the mean value. It is something that is used to describe how widely the data spreads from the mean value. It is usually denoted by σ.

It can be calculated using the following formula:

$Sigma equals the Square root of the fraction the summation from i equals one to n of the quantity x sub i minus the mean of x end quantity squared all over n$

Generally, it is best to use your graphing calculator to find the standard deviation value if your data analysis calls for it. It would be good to review using your graphing calculator’s instruction manual on how to find the simple statistics of mean, median, mode, range, and standard deviation.