Car Repair Costs
Assume that the paired sample data are simple random samples and that the differences have a distribution that is approximately normal.
Car Repair Costs
Listed below are the costs (in dollars) of repairing the front ends and rear ends of different cars when they were damaged in controlled low-speed crash tests (based on data from the Insurance Institute for Highway Safety). The cars are Toyota, Mazda, Volvo, Saturn, Subaru, Hyundai, Honda, Volkswagen, and Nissan. Construct a 95% confidence interval of the mean of the differences between front repair costs and rear repair costs. Is there a difference?
|
Front repair cost
|
936
|
978
|
2252
|
1032
|
3911
|
4312
|
3469
|
2598
|
4535
|
|
Rear repair cost
|
1480
|
1202
|
802
|
3191
|
1122
|
739
|
2769
|
3375
|
1787
|