Question

Cory has received the following grades this term: 75, 87, 90, 88, 79. If he wishes to earn an 85 average, what must he score on his final test?

Answer 1

Answer:

A 91.

Step-by-step explanation:

$\frac{75+87+90+88+79+x}{6}=85\\\\\frac{419+x}{6}=85\\\\(\frac{419+x}{6})6=85*6\\\\419 + x = 510\\\\419-419+x=510-419\\\\\boxed{x = 91}$