Q.12 A special bumper was installed on selected vehicles in a large fleet. The dollar cost of body repairs was recorded for all vehicles that were involved in accidents over a 1-year period. Those with the special bumper are the test group and the other vehicles are the control group, shown below. Each "repair incident" is defined as an invoice (which might include more than one separate type of damage).

Statistic Test Group Control Group

Mean Damage X1 = $ 1,094 X2 = $ 1,755

Sample Std. Dev. s₁ = $ 706 s₂ = $ 803

Repair Incidents n₁ = 15 n₂ = 13

Construct separate 99% confidence intervals for each mean. (Round your intermediate t_crit value to 3 decimal places. Round your final answers to 2 decimal places.)

Mean Damage Confidence Interval

x1 = $1,094 $__________ , $_________

x2 = $1,755 $__________ , $_________