Question

David received three grades of 85,92, and 100 on his first 3 tests. What must he get on the fourth test to get a 90 average?

Answer 1

83

Explanation:

All you have to do here is set up an equation.

(85+92+100+x)/4=90

Then find x which is his 4th test score

85+92+100+x=360

x=360-85-92-100

x=83