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
2.9	2		Electrical		Dave Newton
3.0	6		Mechanical		Dave Newton
4.9	8		Electrical		Bob Jones
1.9	3		Mechanical		Dave Newton
2.8	2		Electrical		Dave Newton
4.9	7		Electrical		Bob Jones
4.1	9		Mechanical		Bob Jones
4.9	8		Mechanical		Bob Jones
4.5	4		Electrical		Bob Jones
4.5	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 if the type of repair is electrical and if Dave Newton performed the service. Enter negative value as negative number.

Round your answers to three decimal places.

b. At the 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 test statistic (to 2 decimals).

Use Table 4 from Appendix B to determine the -value.

The -value is - Select your answer -less than 0.01between 0.01 and 0.025between 0.025 and 0.05between 0.05 and 0.10greater than 0.10Item 6

What is your conclusion?

- Select your answer -The overall model is statistically significantThe overall model is not statistically significantItem 7

c. Is the addition of the independent variable , the repairperson who performed the service, statistically significant? Use .

Compute the test statistic for the significance of (to 2 decimals). Enter negative value as negative number.

Use Table 2 from Appendix B to determine the -value.

The -value is - Select your answer -less than 0.01between 0.01 and 0.025between 0.025 and 0.05between 0.05 and 0.10greater than 0.10Item 9

What is your conclusion?

The addition of Person - Select your answer -is notisItem 10 statistically significant.

What explanation can you give for the results observed?

Person is highly correlated with - Select your answer -months since last servicetype of repairrepair timeItem 11 , so once the effect of that is accounted for the addition of person will not add much.