Copier maintenance. The Tri-City Office Equipment Corporation sells an imported copier on a franchise basis and performs preventive maintenance and repair service on this copier. The data below have been collected from 45 recent calls on users to perform routine preventive maintenance service; for each call, X is the number of copiers serviced and Y is the total number of minutes spent by the service person. Assume that first-order regression model (1.1) is appropriate. i: 1 2 3 ... 43 44 45
Xi: 2 4 3 ... 2 4 5
Yi: 20 60 46 ... 27 61 77
a. Obtain the estimated regression function.
b. Plot the estimated regression function and the data. How well does the estimated regression function fit the data?
c. Interpret bo in your estimated regression function. Does bo provide any relevant information here? Explain.
d. Obtain a point estimate of the mean service time when X = 5 copiers are serviced.