PLEASE SHOW HOW TO SOLVE IN EXCEL SHOW STEPS
Refer to the Johnson Filtration problem introduced in thissection. Suppose that in addition to information on the number ofmonths since the machine was serviced and whether a mechanical oran electrical repair was necessary, the managers obtained a listshowing which repairperson performed the service. The revised datafollow.
Repair Time in Hours | Months Since Last Service | Type of Repair | Repairperson |
2.9 | 2 | Electrical | Dave Newton |
3 | 6 | Mechanical | Dave Newton |
4.8 | 8 | Electrical | Bob Jones |
1.8 | 3 | Mechanical | Dave Newton |
2.9 | 2 | Electrical | Dave Newton |
4.9 | 7 | Electrical | Bob Jones |
4.2 | 9 | Mechanical | Bob Jones |
4.8 | 8 | Mechanical | Bob Jones |
4.4 | 4 | Electrical | Bob Jones |
4.5 | 6 | Electrical | Dave Newton |
- Ignore for now the months since the last maintenance service(x1) and the repairperson who performed the service.Develop the estimated simple linear regression equation to predictthe repair time (y) given the type of repair (x2).Recall that x2 = 0 if the type of repair is mechanicaland 1 if the type of repair is electrical.
- Does the equation that you developed in part (a) provide a goodfit for the observed data? Explain.
- Ignore for now the months since the last maintenance serviceand the type of repair associated with the machine. Develop theestimated simple linear regression equation to predict the repairtime given the repairperson who performed the service. Letx3 = 0 if Bob Jones performed the service andx3 = 1 if Dave Newton performed the service.
- Does the equation that you developed in part (c) provide a goodfit for the observed data? Explain.
- Develop the estimated regression equation to predict the repairtime given the number of months since the last maintenance service,the type of repair, and the repairperson who performed theservice.
- At the .05 level of significance, test whether the estimatedregression equation developed in part (e) represents a significantrelationship between the independent variables and the dependentvariable.
- Is the addition of the independent variable x3, therepairperson who performed the service, statistically significant?Use α = .05. What explanation can you give for the resultsobserved?
