Problem:
The annual incomes of families range from to . In error, the largest income was entered on the computer as . The difference between the mean of the incorrect data and the mean of the actual data is
Answer Choices:
A.
B.
C.
D.
E.
Solution:
The difference between the incorrect sum and the actual sum is . Since this difference is equally shared by all families, the difference between the means is .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions