Chapter 9, Problem 16CR

To determine

To state whether the relationship between the temperature and the time is a direct variation or not.

Answer to Problem 16CR

The ratios are not constant, so the relationship between the temperature and time is not a direct variation.

Explanation of Solution

Given information:

The given graph is:

Calculation :

To find if the relationship is a direct variation, find $\frac{\text{temperature}\left(°\text{F}\right)}{\text{time}\left(\text{h}\right)}$ for different points on the graph.

  $\begin{array}{l}\frac{64}{\text{1}}=64°\text{F/hour}\\ \frac{66}{\text{2}}=33°\text{F/hour}\\ \frac{68}{\text{3}}=22.7°\text{F/hour}\end{array}$

The ratios are not constant, so the relationship between the temperature and time is not a direct variation.