Question 68121: Going into the final exam, which will count as 2 tests, Brooke has a test score of 80, 83,71,61, 95. What score does Brooke need on the final in order to have an average score of 80?
Found 2 solutions by Edwin McCravy, josmiceli:
Answer by Edwin McCravy(20054)   (Show Source):
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Going into the final exam, which will
count as 2 tests, Brooke has a test
score of 80, 83,71,61, 95. What score
does Brooke need on the final in
order to have an average score of 80?
Let x = her final exam grade
sum of all test grades
Average = ------------------------
number of tests
She has taken 5 tests already and the
final exam is the same as if she took
two more tests (7 in all) and made
the same grade on both. Using the
above formula:
80 + 83 + 71 + 61 + 95 + x + x
80 = ---------------------------------
7
390 + 2x
80 = ----------
7
Multiply both sides by 7 to clear of
fractions
7·80 = 390 + 2x
560 = 390 + 2x
170 = 2x
85 = x
She needs to make 85 on the final.
Edwin
Answer by josmiceli(19441)  (Show Source):
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