Chapter 8.3, Problem 40E

To determine

To identify:

The percent of change as an increaseor decrease. Then find the percent of change.

Answer to Problem 40E

The percent of decrease would be $50\%$ .

Explanation of Solution

Given:

Original: 78

New: 39

Concept used:

  $\text{Percent change}=\frac{\text{New}-\text{Original}}{\text{Original}}\times 100\%$

Calculation:

Since new amount is less than original amount, therefore, the percent of change would be a decrease.

Upon substituting our given values in percent change formula, we will get:

  $\begin{array}{l}\text{Percent change}=\frac{\text{New}-\text{Original}}{\text{Original}}\times 100\%\\ \text{Percent change}=\frac{39-78}{78}\times 100\%\\ \text{Percent change}=\frac{-39}{78}\times 100\%\\ \text{Percent change}=-0.5\times 100\%\\ \text{Percent change}=-50\%\end{array}$

Therefore, the percent of change would be $-50\%$ .