Calculator maintenamce. The Ti-City Office Equipment Corporation sells an imported desk calculator on a franchise basis and performs preventive mainte- nance and repair service on this calculator. The data below have been collected from 18 recent calls on users to perform routine preventive maintenance service; for each cail, X is the mumber of machines serviced and Y is the total number of minutes spent by the service person. Assume that the first-order regression model (2.1) is appropriate. i: 1 2 3 4 5 6 8 9 7 6 5 1 5 4 7 3 4 97 86 78 10 75 62 101 39 53 i: 10 11 12 13 14 is 16 17 18 2 8 5 2 5 7 1 4 S 17 49 68 Y: 33 118 65 25 71 105 Summary calculational results are: EY, 1,152, EX; = 81, 2(Y,-= 16,504, 2X, - X)= 74.5, XX, -IXY -D= 1,098. a) Develop the regression equation b) Calculate r c) Does bo provide any relevant information here? Explain