Add all the numbers in the data set to get 55. them divide by 5 to get 11, which is the average or the mean. then find the deviation of each number in the data set. in other words, subtract the mean from each number in the data set. so, for the 1st #--> 1 2nd #--> 6 3rd #--> 1 4th #--> 3 5th #--> 5 add all these numbers up to get 16 and then divide it by 5 to get 3.2 as the mean absolute deviation.
