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.