(i) Compute the average rate of change over the shortest interval to the left of the point of interest (for instance, for the interval from 6 to 9).

Question

(ii) Compute the average rate of change over the shortest interval to the right of the point of interest (for instance, for the interval from 9 to 12).
(iii) Now average the results from steps (i) and (ii), i.e., compute the average of the average rates of change on the left and right sides.

Round your answers to one decimal place.
t 0 2 4 6 9 12
P 6 11 21 32 44 48

b) f′(9) ≈
c) f′(4) ≈