SOLUTION: A student scores 73, 79, 77, 81 on four tests. To receive and 80 average, what must he score on the fifth test?

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Question 358379: A student scores 73, 79, 77, 81 on four tests. To receive and 80 average, what must he score on the fifth test?
Answer by unlockmath(1688) About Me  (Show Source):
You can put this solution on YOUR website!
Hello,
Let x be the fifth text score so we can form and equation as:
(73+79+77+81+x)/5=80
Multiply both sides by 5 toget:
(73+79+77+81+x)=400
Combine like terms:
310+x=400
Subtract 310:
x=90
So a score of 90 is needed.
Got it?
RJ
www.math-unlock.com