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Question:

Jake’s final grade in math class is determined by the average he gets on six tests in the class. So far, Jake has earned a 97, 89, 85, 90, and 99 on the first five tests. What grade must Jake earn on the sixth test in order to get a 93 average in the class?

A 98
Explaination

The average is found by adding the total of all scores and dividing it by the number of scores. Since we know the average Jake wants (93), and we have all the scores from Jake’s tests except one, we can set up an equation, with A representing Jake’s score on the 6th test.
(97 + 89 + 85 + 90 + 99 + A) ÷ 6 = 93
97 + 89 + 85 + 90 + 99 + A = 93 × 6
460 + A = 558
A = 558 - 460 = 98