SOLUTION: Melinda scored 84%, 75% and 77% on her first three tests of the term. What score will she need to earn on her fourth test in order to have an average of 80% on the first four tes

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Question 1155409: Melinda scored 84%, 75% and 77% on her first three tests of the term. What score will she
need to earn on her fourth test in order to have an average of 80% on the first four tests?
Found 2 solutions by Boreal, ewatrrr:
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
average=total/n
so n*average=total
therefore, 4*80=320, the required total
three are 84/75/77, which add to 236
the fourth has to be 320-236=84.

Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi  

scored 84%, 75% and 77% on her first three tests

What score will she need to earn on her fourth test ***Let that be x

average of 80% on the first four tests...

%2884+%2B+75+%2B+77+%2B+x%29%2F4+=++80

%2884+%2B+75+%2B+77%29+%2B+x+=++320

++x+=++320+-++%2884+%2B+75+%2B+77%29

+x+=++320+-++%28236%29

+green%28x+=++84%29

84%,  the score she will need to earn on her fourth test 

   Wish You the Best in your Studies.