Answer Happy

Johnson Filtration, Inc., provides maintenance service for water-filtration systems throughout southern Florida. Suppose that in addition to information on the number of months since the machine was serviced and whether a mechanical or an electrical repair was necessary, the managers obtained a list showing which repairperson performed the service. The revised data follow. Repair Time Months since in Hours Last Service Type of Repair Repairperson 3.0 2 Electrical Dave Newton 2.9 6 Mechanical Dave Newton 4.8 8 Electrical Bob Jones 1.8 3 Mechanical Dave Newton 2.8 2 Electrical Dave Newton 5.0 7 Electrical Bob Jones 4.2 9 Mechanical Bob Jones 4.8 8 Mechanical Bob Jones 4.3 4 Electrical Bob Jones 4.4 6 Electrical Dave Newton a. Develop the estimated regression equation to predict the repair time given the number of months since the last maintenance service, the type of repair, and the repairperson who performed the service. Assume that ay = 1 if the type of repair is electrical and c3 = 1 if Dave Newton performed the service. Enter negative value as negative number. Time = bo + b Months + b2 Type + by Person Round your answers to three decimal places. bo bi b2 b3 b. At the 0.05 level of significance, test whether the estimated regression equation developed in part (a) represents a significant relationship between the independent variables and the dependent variable. Compute F test statistic (to 2 decimals). Use Table 4 from Appendix B to determine the p-value. The p-value is - Select your answer What is your conclusion? - Select your answer -

C. Is the addition of the independent variable 23, the repairperson who performed the service, statistically significant? Use a = 0.05 Compute the t test statistic for the significance of 23 (to 2 decimals). Enter negative value as negative number. Use Table 2 from Appendix B to determine the p-value. The p-value is - Select your answer What is your conclusion? The addition of Person Select your answer - statistically significant. What explanation can you give for the results observed? Person is highly correlated with Select your answer - so once the effect of that is accounted for the addition of person will not add much.