A class of 28 students has 7 juniors and 21 seniors. The average (arithmetic mean) score of the juniors on a test was 73. The average score of the seniors on the test was y. The average score of the entire class on the test was 85. Find y.

Question

Mathematics

Chaya Lucas

6 June, 02:21

A class of 28 students has 7 juniors and 21 seniors. The average (arithmetic mean) score of the juniors on a test was 73. The average score of the seniors on the test was y. The average score of the entire class on the test was 85. Find y.

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Answers (1)

Know the Answer?

Dallas Hurley · Answer 1

89

Step-by-step explanation:

Given that the class has 28 students has 7 juniors and 21 seniors

mean score of the juniors = 73

Therefore, total score of junior = 73 * 7

= 511

mean score of seniors = y

Total score of seniors = 21y

Total score of the class = 511 + 21y

Mean score of the class = 85

Total score of the class = 85 * 28

= 2380

therefore,

511 + 21y = 2380

21y = 2380 - 511

21y = 1869

y = 1869/21

y = 89