Somewhere back in your middle school and high school math classes, you no doubt learned about the mean and standard deviation as fairly fundamental concepts in arithmetic and statistics. You also knew ...

There are two formulae for standard deviation. \(s = \sqrt {\frac{{\sum {{{(X - \bar X)}^2}} }}{{n - 1}}}\) (where n is the sample size). The second formula is a re ...

When reviewing cash flow data for your small business, knowing the standard deviation can help you determine if the numbers are out of whack. Calculating standard deviation manually can be ...