Simple or arithmetic average of a range of values or quantities, computed by dividing the total of all values by the number of values. For example, the mean of 1, 2, 3, 4, and 5 is (15 ÷ 5) = 3. It is the most common and best general purpose measure of the mid-point (around which all other values cluster) of a set of values, but is prone to distortion by the presence of extreme values and may require use of a measure of distortion (such as mean deviation or standard deviation). Also called arithmetic mean. See also median and mode.