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The sum of Ted’s 4 test scores is 340. How much higher must he score on the final exam, compared to the average of the first four exams, if the final exam is worth one third of the final grade for his average to become 87?
A) 10
B) 7
C) 9
D) 6
E) 4
Answer: D
If the sum of the four test scores is 340, their average is 85.
Since the final exam is worth one third of the grade, the first four exams make up the remaining two thirds.
(2/3)(85) + (1/3)F = 87
56.7 + 0.33F = 87
0.33F = 30.3
F = 91
Ted must score 6 points higher than his original average of 85.
