Chapter 1.3, Problem 46E

To determine

To select:the sum of four integers whose average is 15.

Answer to Problem 46E

D. 60

Explanation of Solution

Given information: Average of four integers = 15.

Options are as follows:

1. 37.5
2. 15
3. 30
4. 60
5. Cannot be determined

Calculation:

Let the four integers be $i_1,i_2,i_3$ and $i_4$ .

The sum of four integers can be calculated as follows:

  $\begin{array}{c}\text{Average}=\frac{i_1+i_2+i_3+i_4}{4}\\ 15=\frac{i_1+i_2+i_3+i_4}{4}\left[\text{Substituting the value of average}\right]\\ i_1+i_2+i_3+i_4=\left(15\right)\left(4\right)\\ =60\end{array}$

Thus, the sum of four integers is 60.