KENT WANTS TO IMPROVE HIS MEAN TEST SCORE TO 90.ON HIS FIRST FOUR TESTS HE EARNED 84,93,89,AND 88. WHAT IS THE LOWEST SCORE HE NEEDS ON HIS NEXT TEST TO REACH HIS GOAL?
The first four test scores were 84, 93, 89 and 88, which total 354.
To get a mean of 90 over 5 tests requires a total score of 5 * 90 = 450.
So Kent needs to score 450 - 354 = 96 on the fifth test.
Another way of looking at it is to consider how the scores vary from the desired mean result of 90. So we have 84 = 90 - 6, 93 = 90 + 3, 89 = 90 - 1 and 88 = 90 - 2.
So we have -6, 3, -1 and -2, which total -6. Therefore Kent needs to score 90 + 6 in the fifth test, which gives the same answer as before (96).
