SOLUTION: If your first four test scores have been 89, 79, 75, and 81, what will you have to score on the fifth test to have an average of 80 for all test?

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Question 727632:
If your first four test scores have been 89, 79, 75, and 81, what will you have to score on the fifth test to have an average of 80 for all test?
Answer by checkley79(3341) About Me  (Show Source):
You can put this solution on YOUR website!
(89+79+75+81+x)/5=80
(324+x)/5=80
324+x=5*80
324+x=400
x=400-324
x=76 ans. for the fifth test score.
Proof:
(324+76)/5=80
400/5=80
80=80