SOLUTION: Brian has scored 83, 94, 71, 90, and 75 on his previous five test. What score does he need on his next test so that his average (mean) is an 84?

Algebra ->  Average -> SOLUTION: Brian has scored 83, 94, 71, 90, and 75 on his previous five test. What score does he need on his next test so that his average (mean) is an 84?      Log On


   

Question 986275: Brian has scored 83, 94, 71, 90, and 75 on his previous five test. What score does he need on his next test so that his average (mean) is an 84?
Answer by abhimessi(4) About Me  (Show Source):
You can put this solution on YOUR website!
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MEAN=SUM OF ALL MARKS/NO OF HIS SCORES
GIVEN MEAN=84 LET THE MARK HE SCORES ON NEXT TEST BE X
84=83+94+71+90+75+X WHOLE DIVIDED BY 6
IF YOU TAKE 6 TO OTHER SIDE,THE OPERATION WILL CHANGE FROM DIVISION TO MULTIPLICATION
84*6=413+X 504-413=X
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X=91 MARK HE SHOULD SCORE NEXT=91
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