Question

What is the mean absolute deviation for the data shown in the stem-and-leaf-plot?

A.
6


B.
9.3


C.
9.7


D.
19

Answer 1

Mean Absolute Deviation or MAD is the mean of the difference of the numbers from the mean.

So first let's find the mean.

Data:

2, 10, 16, 21, 27, 38

Add them up and divide by how many there are:

2 + 10 + 16 + 21 + 27 + 38 = 114

114 / 6 = 19

So the mean is 19.

Now subtract the values from 19.

38 - 19 = 19
27 - 19 = 8
21 - 19 = 2
19 - 16 = 3
19 - 10 = 9
19 - 2 = 17

Find the mean of these differences.

19 + 8 + 2 + 3 + 9 + 17 = 58

58 / 6 ≈ 9.7