A stunt person is shot out of a cannon from a platform 8 feet off of the ground. The height of the stunt person can be modeled as a function of time in seconds. The function is represented on the graph below.
Enter the average rate of change for the height of the stunt person, measured as feet per second, between 8 seconds and 17 seconds. Enter your estimate as "the nearest whole number."
Hint: "average rate of change" is a whole number estimate of a slope, including the sign.