Answer
The answer is below.
Work Step by Step
A) The values in the table, in order from left to right (as the table is listed in the book) are: 10, 5, -20, 100, 35, 25, 15. (In order to obtain these values, plug in the value for t above them into the equation and then solve the equation for f(t).
C) In order to do this, draw a horizontal line at f =20, and then estimate the value of t when the line intersects the line graphed in part b. The actual value is:
$ f = 5/9(20-32) \\ f = -6.7$