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.