Sales OHaganBooks.com fits the curve to its weekly sales figures...

Sales OHaganBooks.com fits the curve

to its weekly sales figures from Exercise 47, as shown in the following graph:

a. Compute the derivative function w ‘(t).

b. According to the model, what was the rate of increase of sales at the beginning of the second week (t = 1)?

c. If we extrapolate the model, what would be the rate of increase of weekly sales at the beginning of the 8th week

(t = 7)?