SOLUTION: a student received grades of 75, 90, and 83 on three math tests. What grade does the student need on the fourth test to have an average test score of at least 85?

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Question 972542: a student received grades of 75, 90, and 83 on three math tests. What grade does the student need on the fourth test to have an average test score of at least 85?
Found 2 solutions by stanbon, lwsshak3:
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
a student received grades of 75, 90, and 83 on three math tests. What grade does the student need on the fourth test to have an average test score of at least 85?
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Let the the 4th test score be "x"::
Solve for "x"::
(75+90+83+x)/4 >= 85
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248+x >= 340
x >= 92
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Cheers,
Stan H
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Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
a student received grades of 75, 90, and 83 on three math tests. What grade does the student need on the fourth test to have an average test score of at least 85?
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let x=score student needs on the 4th test
%2875%2B90%2B83%2Bx%29%2F4=85
%28248%2Bx%29%2F4=85
248+x=4*85=340
x=340-248
x=92
score student needs on the 4th test: 92