Mean

The mean is of a group of numbers is one way to express their average. To find the mean, the numbers are added and divided by the quantity of numbers in the group. For example: to find the mean of 3, 4, 6, and 7, we add them together: $3+4+6+7=20$. Then we divide them by the quantity of numbers in the group, which is 4. $20/4=5$.

Most spreadsheet programs and computer languages consider average to be the mean, but there are three common types of average. Often the median is far from the mean, when values are skewed in one direction (see also mode).