Question

A student has gotten the following grades on his tests:89, 94, 75, 79. What is the minimum grade he must get on the last test in order to have an average of 83?

Answer 1

Answer:

Explanation:

Let the minimum grade that the student must get = y

Expected average grade = 83

Therefore:

$\frac{89+94+75+79+y}{5}=83$

We solve the equation above for y:

$\begin{gathered} \frac{89+94+75+79+y}{5}=83 \\ 89+94+75+79+y=83\times5 \\ 337+y=415 \\ y=415-337 \\ y=78 \end{gathered}$

The minimum grade required to get an average of 83 is