Question 353055:  Going into the final exam, which counts as two grades, you have the following test scores of 84, 78, 64, and 88. What score do you need on the final exam in order to have an average of 80? 
 Answer by nerdybill(7384)      (Show Source): 
You can  put this solution on YOUR website! Going into the final exam, which counts as two grades, you have the following test scores of 84, 78, 64, and 88. What score do you need on the final exam in order to have an average of 80?
 
Let x = final exam score 
the
 
(x + x + 84 + 78 + 64 + 88)/6 = 80
 
(2x + 84 + 78 + 64 + 88)/6 = 80
 
(2x + 314)/6 = 80
 
2x + 314 = 480
 
2x = 166 
  
x = 83 
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