Question 776764: the average of 5 numbers is 10. the first four numbers are 8, 9, 10, 11. find the fifth number
Found 2 solutions by FrankM, stanbon:
Answer by FrankM(1040)   (Show Source):
You can put this solution on YOUR website! For 5 number to average 10, they must add to 50, as 50/5 = 10, right?
Your 4 numbers sum to 38, so the missing number is 50 - 38 = 12
Answer by stanbon(75887)  (Show Source):
You can put this solution on YOUR website! the average of 5 numbers is 10. the first four numbers are 8, 9, 10, 11. find the fifth number
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Let the 5th number be "x":
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Equation:
(8+9+10+11+x)/5 = 10
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(38+x) = 50
x = 12
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Cheers,
Stan H.
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