Question 671355: Leon must have made a mean score of 90 on his math quizzes to earn an A. So far, he has received grades of 88,85,91,92,94,81,86,98. What grade must he earn on his final quiz?
Found 3 solutions by ewatrrr, stanbon, solver91311:
Answer by ewatrrr(24785)   (Show Source):
Answer by stanbon(75887)  (Show Source):
You can put this solution on YOUR website! Leon must have made a mean score of 90 on his math quizzes to earn an A. So far, he has received grades of 88,85,91,92,94,81,86,98. What grade must he earn on his final quiz?]
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His final quiz will be his 9th quiz.
To average 90 he needs 9*90 = 810 points
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He needs 810-(88+85+91+92+94+81+86+98) = 95 on his 9th quiz
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Cheers,
Stan H.
Answer by solver91311(24713)  (Show Source):
You can put this solution on YOUR website!
In order to have a mean score of greater than or equal to X on Y equal weight tests, then you must have a total of greater than or equal to XY. You have a list of eight exams. Presumably the "final quiz" is the only other one that has to be taken, so there are a total of 9 quizzes. Add up the scores of the quizzes already taken and subtract from 9 times 90. The result will be the score required for the desired average.
John
My calculator said it, I believe it, that settles it
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