Question 1019510: The first three scores of each of the four studends are shown. Each test is 100 points. Each student hopes to maintain a mean score of 85. Find the score needed by each student on the fourth test to have mean score of 85, or explain why such value is not possible.
A. Lisa: 78, 80, 100
B. Mary: 90, 92 ,95
C. Lina: 79, 80, 81
D. Willie: 65, 80, 80
Answer by LinnW(1048) (Show Source):
You can put this solution on YOUR website! For 4 tests to have an average of exactly 85 we
need the total of the 4 tests to be 4*85 = 340
Lisa needs 340 - (78+80+100) , 340 - 258 = 82
Mary needs 340 - (90+92+95) = 63
Lina needs 340 - (79+80+81) = 100
Willie needs 340 - (65+ 80+ 80 ) = 115
Since the score Willie needs is above 100 he cannot achieve his goal.
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