Answer:
2.4
Explanation:
You want the average rate of change on the interval [-9, -4] for the graphed function.
Average rate of change
The average rate of change (m) is the slope of the line between the points at the ends of the interval. For function f(x) on interval [a, b], this is ...
m = (f(b) -f(a))/(b -a)
Application
For the function f(x) on the interval [-9, -4], the average rate of change is ...
m = (f(-4) -f(-9))/(-4 -(-9)) = (-4 -(-16))/5 = 12/5 = 2.4
The average rate of change of f(x) on [-9, -4] is 2.4.