SOLUTION: These are Joey's grades for this marking period:84,92,90,82,87.What would he have to get on his next test to have a mean average of 88?

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Question 63226: These are Joey's grades for this marking period:84,92,90,82,87.What would he have to get on his next test to have a mean average of 88?

Found 2 solutions by 303795, Cintchr:
Answer by 303795(602) (Show Source):
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He will have completed 6 tests with an average of 88. The total scores of the six tests will have to be 6 x 88 = 528.
The current total of the tests he has completed is 84+92+90+82+87=435
The next test score will therefore need to be 528-435 = 93.

Answer by Cintchr(481) (Show Source):
You can put this solution on YOUR website!
Current scores: 84,92,90,82,87
Current # of assignments: 5
Current Total: 435
Current Average: 69

Final scores: 84,92,90,82,87,x
Final # of assignments: 6
Final Total: 345+x or 88*6 = 528
Final Average: 88

A x N = T
Average times Number equals Total
(work this for both sets of numbers)
F:
C:
Subtract the two equations
T:
He needs a 93 to raise his 69 to an 88