SOLUTION: You have taken 3 tests and have an average of 72 points. If you score 100 points on each of the rest of your tests, how many more tests do you need to take to raise your average to
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Question 150536: You have taken 3 tests and have an average of 72 points. If you score 100 points on each of the rest of your tests, how many more tests do you need to take to raise your average to 88 points? Answer by checkley77(12569) (Show Source):
You can put this solution on YOUR website! (3*72+x*100)/(x+3)=88
(216+100x)/(x+3)=88
216+100x=88(x+3)
216+100x=88x+264
100x-88x=264-216
12x=48
x=48/12
x=4 more tests with grades of 100 should do it.
Proof:
(216+4*100)/(4+3)=88
(216+400)/7=88
616/7=88
88=88
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