Question

Jane has scores of 84, 92, and 89 on her first 3 exams. What does she need to score on the next exam so that her overall average will be 90?

Answer 1

For the average of 4 exams to be 90
the total of all 4 exams must be `4 xx 90 = 360`

Let fourth exam score be `x`

`84 + 92 +89 + x = 360`
`265 + x = 360`
`x = 95`

She will need to score `95` on her fourth exam to average `90`