Answer: 98
Explanation:
Let the test score be x
Recall,
mean or average score = sum of scores/number of scores
From the information given,
the scores are 92, 86, 83, 90, and 91. By adding x,
number of scores = 6
Mean score = 90
Thus, we have
(92 + 86 + 83 + 90 + 91 + x)/6 = 90
(442 + x)/6 = 90
By cross multiplying,
442 + x = 90 * 6 = 540
Subtracting 442 from both sides, we have
442 - 442 + x = 540 - 442
x = 98
She needs to score 98
