The function 𝑓 is of the form 𝑓𝑥=𝑎+𝑏log𝑥−1
𝑓6=7 and 𝑓9=11 
D) Find the average rate of change of 𝑓 on the interval 6≤𝑥≤9 
E) Use the average rate of change from part (D) to estimate 𝑓11
F) Using the shape of the graph of 𝑓𝑥 explain how one knows that the answer to (E) overestimates the actual value of 𝑓11.