Question

Martin earned the following scores on his last five tests. 98, 78, 84, 75, 91 What is the mean absolute deviation of his scores?

Answer 1

84 would be the answer.

Answer 2

7.44√

Explanation:

find the average of his scores:

98 +78+84 +75 +91 = 426/5 = 85.2

now find the difference between the average and each test score:

98 - 85.2 = 12.8

85.2 -78 = 7.2

85.2 - 84 = 1.2

85.2 -75 = 10.2

91-85.2 = 5.8

total those and divide by the number of tests

12.8 + 7.2 + 1.2 +10.2 +5.8 =37.2/5 = 7.44