Question

Please Help me Asap

Rob's first four test scores are 80, 85, 100, and 85. What does he have to score on the last test in order to have a test average of 90?
options:

90


100


10


95

Answer 1

100

Explanation:

Given Average After writing a last test=90

let the last test score be x

Now given

`(80 + 85 + 100 + 85 + x)/(5) = 90`

`80 + 85 + 100 + 85 + x = 450`

`x + 350 = 450`

`x = 100`

I hope it helped you