Problem:
On an algebra quiz, of the students scored 70 points, scored 80 points, scored 90 points, and the rest scored 100 points. What is the difference between the mean and the median of the students' scores on this quiz?
Answer Choices:
A.
B.
C.
D.
E.
Solution:
Because over of the students scored 90 or lower, and over of the students scored 90 or higher, the median score is 90 . The mean score is
for a difference of .
The problems on this page are the property of the MAA's American Mathematics Competitions