Question

9) Gabriel took three math tests last semester. He scored a 91 on the first test, a

Answer 1

The average of anything can be calculated by adding up all the terms and dividing by the number of terms.

In this case,

the number of terms = 3

x = the missing test score.

(91 + 72 + x) / 3 = 80

Let's multiply both sides by 3

91 + 72 + x = 240

Combine like terms.

163 + x = 240

Subtract 163 from both sides

x = 77

Carlos scored a 77 on his third test.