You scored 88,92, and 87 on three tests. Write and solve an equation to find the score you need on the fourth test so that your mean test score is 90.

Question

You scored 88,92, and 87 on three tests. Write and solve an equation to find the score you need on the fourth test so that your mean test score is 90.

Answer 1

You need 93 to get an average 90 grade

(87+88+92 + x)/4 = 90

87+88+92 +x = 90(4) = 360

267 + x = 360

x = 360-267 = 93