(Solved): 4.3. Refer to Copier maintenance Problem 1.20. a. Will b0 and b1 tend to err in the same dir ...

4.3. Refer to Copier maintenance Problem 1.20. a. Will $b_0$ and $b_1$ tend to err in the same direction or in opposite directions here? Explain. b. Obtain Bonferroni joint confidence intervals for ${\beta }_0$ and ${\beta }_1$, using a 95 percent family confdence coefficient. c. A consultant has suggested that ${\beta }_0$ should be 0 and ${\beta }_1$ should equal 14.0. Do your joint confidence intervals in part (b) support this view? *1.20. 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.