Demand for oil changes at Garcia’s Garage has been as follows:
Month Number of oil changes
January ......... 41
February .......... 46
March ......... 57
April ......... 52
May ......... 59
June ......... 51
July ......... 60
August ......... 62
a. Use simple linear regression analysis to develop a forecasting model for monthly demand. In this application, the dependent variable, Y is monthly demand and the independent variable, X is the month. For January, let X = 1; for February. Let X = 2; and so on.
b. Use the model to forecast demand for September, October, and November Here X = 9, 10, and 11, respectively.