Question

Ann's grade is the average of four scores: three chapter tests and a final

that counts as two chapter tests. She scored 72, 90, and 75 on the chapter
tests. What score does she need on the final to have a grade of at least 80?

Answer 1

f = 81.5

Explanation:

hello!

to be able to find the score she needs to have a final grade of at least 80, we use the following equation:

`(72+90+75+2f)/(5)=80`

To get rid of the denominator, we multiply both sides of the equation by 5. Once we do, 5 gets canceled and 80 * 5 = 400. Therefore:

237 + 2f = 400.

Transpose, then simplify.

2f = 400 - 237

2f = 163

Divide both sides by 2 to isolate f:

f = 81.5