Returns the average of the absolute deviations of values from their mean.
AVEDEV(number1, number2, ... number30)
number1 to number30 are up to 30 numbers or ranges containing numbers.
AVEDEV calculates the mean of the numbers, then the absolute (positive signed) deviation of each number from that mean. It returns the average of those deviations. The formula used is
AVEDEV(1, 4, 7)
returns 2. The mean is 4, and the absolute deviations from the mean are 3, 0, 3 respectively.