Your original grades on your exams were: 75, 85, 90, 90,
100, 75, 80, 100, 90.
You retake the exams and now your scores are:
85, 85, 100, 90, 100, 85, 80, 100, 90.
By how many percentage points did you improve
your average score?
Hint: Find the mean of both sets of data. Then
find the difference between the two. Round to
the nearest %.