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 ...

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 ...

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 ...

The patterns seen in math are also evident on the LTT Reading test (click on tabs to see reading scores) but at mercifully smaller sizes. Since 2012, the 10th percentile reading scores are down 31 ...

In response to my article, Is the Stock Market Too Concentrated?, which relied upon standard-deviation calculations to assess investment risk, a reader wrote: “My problem [with your argument] is ...

Standard deviation is a measurement of market volatility. Learn how investors use standard deviation in the MoneySense Glossary. Standard deviation (σ) is an investing metric used to measure the ...