Johnson Filtration, Inc.

Johnson Filtration, Inc. provides maintenance service for water-filtration systems. Data that follow show the repair time in hours, the months since last service, the repair type and the repair person for a sample of 10 maintenance service calls.

Repair Time
(hours) Months Since Type of
last service 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




Ignore the months since last service and the repairperson data. Let type of repair be a dummy variable with 0 indicating a mechanical repair and 1 indicating an electrical repair. Develop the estimated simple linear regression equation that can be used to predict the repair time based on the type of repair (to 3 decimals).
Time = ?????? + ?????? Type


Ignore the months since last service and the type of repair data. Let repairperson be a dummy variable with 0 indicating Bob Jones and 1 indicating Dave Newton. Develop the estimated simple linear regression equation that can be used to predict the repair time based on the repairperson (to 2 decimals).
Time = ???? + ????? Person