Question

A dog trainer compared mean numbers of lessons for two

groups of dogs to learn a new trick.

Mean number of lessons Mean Absolute Deviation (MAD)

Group A 15

3

Group B 9

3

Which statement about the data is true?

A. The MAD for group A is more than the MAD for group B.

B. The mean number of lessons for group A is greater than the mean

for group B by 6 MADs.

C. The mean number of lessons for group A is greater than the mean

for group B by 2 MADs.

D. On average, the dogs in group B required more lessons than the

dogs in group A.

Answer 1

C. The mean number of lessons for group A is greater than the mean for group B by 2 MADs.

Explanation:

Mean of Group A is greater than the mean of group B. The mean absolute deviation for the group A and B is 3. The different between the mean is 6 (15 - 9)

Number of mean absolute deviations is :

Difference between mean of two groups / MAD

6 / 3 = 2.