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 ...

Standard deviation is an important measure of spread or dispersion. When comparing distributions, it is better to use a measure of spread or dispersion (such as standard deviation or ...

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 ...