Patrycia's overall grade in her physics class is based solely on the average of her scores on 6 unit tests. The grade she received on the first 5 tests are as follows: 89, 93, 95, 92, 90. What grade does Patrycia need to earn on her 6th unit test to end up with a 90% in the class?

A.

76.5%

B.

81%

C.

90%

D.

92.5%

Question

Mathematics

Kennedi Grimes

13 August, 16:20

Patrycia's overall grade in her physics class is based solely on the average of her scores on 6 unit tests. The grade she received on the first 5 tests are as follows: 89, 93, 95, 92, 90. What grade does Patrycia need to earn on her 6th unit test to end up with a 90% in the class?

A.

76.5%

B.

81%

C.

90%

D.

92.5%

+1

Answers (2)

Know the Answer?

Nayeli Daniel · Answer 1

It would be B. 81%

I tested out each answer by finding the average:

89 + 93 + 95 + 92 + 90 + 81 = 540

540 / 6 = 90

Vicente Carney · Answer 2

(89 + 93 + 95 + 92 + 90 + x) / 6 = 90%

(459 + x) / 6 = 90% (multiply by 6)

459 + x = 540

x = 540 - 459

x = 81

check ...

(459 + 81) / 6 = 90%

540/6 = 90%

90% = 90% (correct)

She would need to have an 81