Question

Andy has grades of 84, 65 and 76 on three math tests. What grade must he obtain on the next test to have an average of exactly 80 for the four tests?

Answer 1

`95`

Explanation:

Required Average `=80`

Let the required grade be `x`.

`"Average"=("Sum of" \ n \ "numbers")/n`

So

`80=(76+84+65+x)/4`

`320=225+x`

`x=320-225`

`x=95`

Therefore, the required grade is `95`.