First, you would find the mean of the data. Once you have the number, you would find the difference between the mean and the other numbers. Once you have all of those numbers, you find the mean of that set. For example:
The mean of this set is 9. We then use this number to find the difference between all of the numbers. So 14-9= 5, 9-7=2, 9-6=3, 9-5=4, 13-9=4. Finding the mean of 5, 2, 3, 4, and 4 results in 18/5 or 3.6
3.6 is the mean absolute deviation.
