Each student in a seventh grade physical education class did a one minute sit up test at the beginning of the six weeks period, and then did the same test again at the end of the six weeks period. The data is recorded in the dot plots below.
x xx
х
х
X
х
XX
х
х X

X
х
30
50
40
xx xxx
35
CART
40 45
Number of Sit Ups in One Minute
At Beginning of Six Weeks Period
60
45 50 55
Number of Sit Ups in One Minute
At End of Six Weeks Period
Based on the dot plot data, the mean number of sit ups at the beginning of the six weeks period is 40 sit ups per minute with a
mean absolute deviation of 7. The mean number of sit ups at the end of the six weeks period is 48 sit ups per minute with a
mean absolute deviation of
From the data, it can be concluded that the students' number of sit ups had more variability at the
of the six weeks
period.