Question

During the first three quarters you got a 60, 80, 75. Youwant at least a 70, C-, average. What do you need toget on the last quarter?

Answer 1

Average: sum the quarters and divide by the number of quarters:

(60+80+75+x)/ 4 ≥ 70

Solve for x

(215+x)/ 4 ≥ 70

215+x ≥ 70 (4)

215+ x ≥ 280

x ≥ 280-215

x ≥ 65