Chapter 8.8, Problem 39IP

To determine

Find how much score Nomar need to earn on the fifth test in order to achieve his goal.

Answer to Problem 39IP

Nomar needs at least 79 in the fifth test.

Explanation of Solution

Given:

Nomar has earned scores of 73,85,91 and 82 on the first four of five tests for the grading period. He would like to finish the grading period with a test average of at least 82. What score does Nomar need to earn on the fifth test in order to achieve his goal?

Concept Used:

Let the n is the Nomar`s 5^th test score.

Nomar has earned scores of 73,85,91 and 82 on the first four of five tests.

He would like to finish the grading period with a test average of at least 82.

The required inequality: $\frac{n+73+85+91+92}{5}\ge 82$

Calculation:

The required inequality: $\frac{n+73+85+91+92}{5}\ge 82$

  $\begin{array}{l}5·\frac{n+73+85+91+92}{5}\ge 5·82\\ n+331\ge 410\\ n+331-331\ge 410-331\\ n\ge 79\end{array}$

Nomar needs at least 79 in the fifth test.

Thus, Nomar needs at least 79 in the fifth test.