What is the definition of "mean absolute deviation?"

The mean absolute deviation of a number set is the average distance between each value and the mean. This is obtained by finding the mean of the set, determining the absolute value difference between each number, and the mean and calculating the average of these differences.

For example, the mean of data set {4, 6, 12, 8, 5} is 7 (35 / 5). The absolute value difference between each value and the mean is 3, 1, 5, 1 and 2. The average of these differences is 2.5 (12 / 5). Therefore, the mean absolute deviation of set {4, 6,12, 8, 5} is 2.5.