Last month, the seventh grade and eighth-grade math classes at moore middle school collected canned goods for the local food shelter. the dot plots below show the number of canned goods collected by the classes.

the mean absolute deviation for each grade level is 1.6. the difference between the mean number of canned goods collected by each grade level is how many times the mean absolute deviation?
a. 5
b. 3
c. 4
d. 8

To answer this you need to find the mean for each set of data and then compare this to the mean absolute deviation.

The mean for the 7th grade canned soup was 21 (to get this I added all the numbers together and then divided by 20).

For the 8th grade class, I got 13 (a sum of 325/25).

The difference of these 2 is 6.

Then you divide 6 by 1.5 (the mean absolute deviation ) to find out how many times.

The answer is 4, letter C.

Um what? rephrase that ?