Final answer:
The average rate of change of a new car's value, which is initially $28,400 and $5,000 after 9 years, is a decrease of $2,600 per year.
Step-by-step explanation:
The average rate of change of a car's value can be calculated using the formula for slope, which is the change in value over the change in time.
In this case, the initial value of the car is $28,400 and after 9 years, the value is $5,000. To find the average rate of change, subtract the final value from the initial value and then divide by the number of years.
The calculation is as follows:
Average rate of change = (Final value - Initial value) / (Final time - Initial time)
Average rate of change = ($5,000 - $28,400) / (9 years - 0 years) = -$23,400 / 9 years = -$2,600 per year
Therefore, the car's value decreases by an average of $2,600 each year over the course of 9 years.