SOLUTION: Roberto's grades on four test were 90, 65, 82, and 73. What must be his lowest grade on the next test in order to have an average greater than 80?

Question 930132: Roberto's grades on four test were 90, 65, 82, and 73. What must be his lowest grade on the next test in order to have an average greater than 80?
Answer by TimothyLamb(4379) (Show Source): You can put this solution on YOUR website!
(90 + 65 + 82 + 73 + x)/5 = 80
(90 + 65 + 82 + 73) + x = 80*5
x = 80*5 - (90 + 65 + 82 + 73)
x = 90
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answer:
he must score better than 90 on the 5th test to get a five-test average score over 80
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