An administrator at the Department of Motor Vehicles (DMV) tracked the average wait time from month to month.

Question

Average waiting time at the DMV
Month Waiting time (minutes)
May 43
June 35
July 43
August 42
September 36
According to the table, what was the rate of change between June and September?
Round your answer to the nearest tenth.
minutes per month

Answer 1

To find the rate of change between June and September, we first need to identify the waiting times for both months:

• June: 35 minutes
• September: 36 minutes

Next, we calculate the change in waiting time from June to September:

\[ \text{Change in waiting time} = \text{Waiting time in September} - \text{Waiting time in June} = 36 - 35 = 1 \text{ minute} \]

Now, we find the number of months between June and September. This is from June (1 month) to September (3 months), so there are 3 months in total:

Next, we calculate the rate of change:

\[ \text{Rate of change} = \frac{\text{Change in waiting time}}{\text{Number of months}} = \frac{1 \text{ minute}}{3 \text{ months}} \approx 0.3333 \text{ minutes per month} \]

Rounding this to the nearest tenth gives us:

\[ \text{Rate of change} \approx 0.3 \text{ minutes per month} \]

Therefore, the rate of change between June and September is approximately 0.3 minutes per month.