Johnson Filtration, Inc. provides maintenance service for water-filtration systems. 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.

Click on the datafile logo to reference the data.

Repair Time	Months Since
in Hours	Last Service	Type of Repair	Repairperson
2.9	2		Electrical		Dave Newton
3.0	6		Mechanical		Dave Newton
4.8	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

a.Ignore for now the months since the last maintenance service () and the repairperson who performed the service. Develop the estimated simple linear regression equation to predict the repair time () given the type of repair (). Recall thatif the type of repair is mechanical andif the type of repair is electrical (to 2 decimals).

Time= + Type

b.Does the equation that you developed in part (a) provide a good fit for the observed data? Explain. (to 4 decimals)

- Select your answer -NoYesItem 3 , because the-value of shows that the relationship is - Select your answer -significantnot significantItem 5 for any reasonable value of .

c.Ignore for now the months since the last maintenance service and the type of repair associated with the machine. Develop the estimated simple linear regression equation to predict the repair time given the repairperson who performed the service. Letif Bob Jones performed the service andif Dave Newton performed the service (to 2 decimals). Enter negative value as negative number.

Time= + Person

d.Does the equation that you developed in part (c) provide a good fit for the observed data? Explain. - Select your answer -Repairperson is a better predictor of repair time than the type of repairBoth predictors are about the sameType of repair is a better predictor of repair time than the repairpersonItem 8