A. 11
Step-by-step explanation:
The average rate of change of the given function over the interval [2,6] is simply the slope of the secant line connecting the point (2,f(2)) and (6,f(6)).
This implies that, the average rate of change over [2,6]
From the table f(6)=71
Since we want the average rate of change to be 15, we have;
This implies that;
The correct choice is A.