Question

On two​ examinations, you have grades of 83 and 89. there is an optional final​ examination, which counts as one grade. you decide to take the final in order to get a course grade of​ a, meaning a final average of at least 90

Answer 1

Let's say you get x on the third examination.
The average of all three examinations must be at least 90 to get an A.


`(x + 83 + 89)/(3) \ge 90`


`x + 172 \ge 270`


`x \ge 98`

In order to get an A, you must get at least a 98 on the third examination.