Data : 12, 16, 10, 20, 12 ; what is the mean deviation of these data ?
3.2
4.6
5.2
4.4
3.8
arithmetic mean : m = 70 / 5 = 14 ; s = (4 + 2 + 2 + 2 + 6) / 5 = 16 / 5 = 3.2 ; . pg. 112. Correct answer is A.
