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 ...

In statistics, the average amount a number varies from the average number in a series of numbers. THIS DEFINITION IS FOR PERSONAL USE ONLY. All other reproduction requires permission.

The Journal of Educational Research is a well-known and respected periodical journal that reaches an international audience of educators and others concerned with cutting-edge theories and proposals.

Standard deviation is a common statistical measurement and is defined by Oxford Dictionaries as: ‘A quantity expressing by how much the members of a group differ from the mean value for the group.’ In ...

When you're trying to estimate the time between the beginning and the end of any project, the critical path follows the longest route. The standard deviation, on the other hand, uses the the most ...

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 ...