Chapter 1.6, Problem 9E

To determine

To express: the given quantity in terms of the indicated variable.

Answer to Problem 9E

  $\frac{160+s}{3}$ .

Explanation of Solution

Given:

The given quantity is “the average of three test score”.

The first two scores are $78\text{ and }82$ respectively.

Concept used:

Average is to find by sum of all terms divided by number of terms.

  $Avg=\frac{\text{sum of all terms}}{\text{Total num}\text{. of terms}}$

Calculation:

According to question, the first two score are:

  $\begin{array}{l}\text{score}1:78\\ \text{score}2:82\end{array}$

And the third score is s.

As the average is to find by sum of all terms divided by number of terms.

Therefore,

  $\begin{array}{l}Avg=\frac{78+82+s}{3}\\ =\frac{160+s}{3}\end{array}$

Hence,the average of three test scoreis $\frac{160+s}{3}$ .