A tele marketing company wants to know if sales go up as they call more people per dat but spend less time per call. The following is the data from nine randomly selcted days. The information is the number of calls the salesperson makes in a day and the total amount of sales (in thousands of dollars).
Calls 25 29 33 37 43 48 52 55 67
Sales 3.7 4.2 4.2 5.0 4.7 5.3 4.9 5.6 5.9
a) Generate the estimated OLS line.
b.) Interpret the estimated slope coefficient from your line in part a.