To determine the rate of change in the average waiting time between April and May at the DMV, we follow these steps:
1. Identify the waiting times for April and May:
- In April, the average waiting time was 24 minutes.
- In May, the average waiting time was 7 minutes.
2. Find the difference in waiting times between these two months:
- The difference is calculated by subtracting the waiting time in May from the waiting time in April.
- Difference = Waiting time in May - Waiting time in April = 7 minutes - 24 minutes = -17 minutes.
3. Calculate the rate of change:
- The rate of change allows us to understand how much the waiting time changed per month.
- Since we are looking at the change from April to May, the time interval is 1 month.
- The rate of change is thus the difference in waiting times divided by the time interval:
[tex]\[
\text{Rate of change} = \frac{\text{Difference in waiting times}}{\text{Time interval}} = \frac{-17 \text{ minutes}}{1 \text{ month}} = -17 \text{ minutes per month}.
\][/tex]
Therefore, the rate of change in the average waiting time between April and May is [tex]\(\boxed{-17}\)[/tex] minutes per month.
