Mean

The mean is the most often-used measure of central tendency and is usually defined as the sum of all the scores in a data set divided by the number of observations. It can also be defined as the point about which the sum of the deviations is equal to zero.

The formula for the computation of the mean is as follows:

where

• The letter X with a line above it (also called “X bar”) is the mean value of the group of scores or the mean.
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• The Σ, or the Greek letter sigma, is the summation sign, which directs you to add together what follows it.
• The X is each individual score in the group of scores.
• n is the size of the sample from which you are computing the ...