Answer:
-.82
Step-by-step explanation:
To find the average rate of change over an interval, you use rise over run with the first point and the last point (in this case, the first point is (50, 35.8) and the last point is (60, 27.6)). This will give you an average rate of change of -.82.
In the context of this problem, -.82 is how much your expected remaining life span decreases each year.
