Question

After six 100 point tests you have 552 points how many points do you need to score on your next 100 point test to have a mean score of 91 points

Answer 1

The mean of the 6 tests:
552 ÷ 6 = 92
The initial amount of points plus the new score = new total, divided by the 7 total tests = new mean score
552 + 85 = 637 ÷ 7 = 91

You would need to score an 85 to have a mean score of 91 points.

Answer 2

To have a mean of 91, we need a total of 91 x 7 = 637

637 - 552 = 85

so the next test needs a score of 85