Question

Debbie received grades of 90, 94, 85, and 89 on four math tests. What is the lowest grade that Debbie can receive on the fifth test in order for her average to be greater than 90?

a) 92

b) 87

c) 91

d) 89.5

Answer 1

Debbie would need a score of 92 on the fifth test to have an average greater than 90.

Step-by-step explanation:

In order for Debbie's average to be greater than 90, the sum of her grades on the five tests must be greater than 5 * 90 = 450. Her current sum of grades on four tests is 90 + 94 + 85 + 89 = 358. To find the lowest grade she can receive on the fifth test, we subtract 358 from 450: 450 - 358 = 92.

Therefore, the lowest grade that Debbie can receive on the fifth test in order for her average to be greater than 90 is 92.