Chapter 8.1, Problem 69E

We opened this section with a study showing that late in the semester, procrastinating students reported more symptoms of physical illness than their nonprocrastinating peers.

a. At the beginning of the semester, procrastinators reported an average of 0.8 symptoms, increasing at a rate of 0.-15 symptoms per week. Write a function that models the average number of symptoms after r weeks.

b. At the beginning of the semester, nonprocrastinators reported an average of 2.6 symptoms, increasing at a rate of 0.15 symptoms per week. Write a function that models the average number of symptoms after x weeks.

c. By which week in the semester did both groups report the same number of symptoms of physical illness? For that week, how many symptoms were reported by each group? How is this shown in Figure 5.1 on page 542?