Question

Insurance adjusters were concerned about the high repair cost that they are paying for garage A. They design a study to verify their suspicions. 10 damaged cars are randomly selected from a pool of cars, and each car was taken to both garage A and Garage B for an estimate. Does the following data confirm their suspicions? Use a=0.01, what is the p=value?

Damaged Cars	Garage A Estimate	Garage B Estimate
1	2.1	2.0
2	4.5	3.6
3	6.3	5.9
4	3.0	2.8
5	1.2	1.3
6	5.4	5.0
7	7.3	6.4
8	9.5	8.6
9	10.1	9.1
10	7.6	7.2

Answer 1

null Hypothesis alternate Hypothesis 0 0 for 0.01 level with right tailed test and n-1-9 degree of freedom, critical value of t- Decision rule 2.8214 reject Ho if test statistic t>2.821 S. No 1 2 2 difference(d) x1-x2 2.1 4.5 6.3 2 0.010000 0.810000 0.160000 0.040000 0.010000 0.160000 0.810000 0.810000 1.000000 0.160000 2d2-3.97 0.9 0.4 3.6 1.2 5.4 7.3 9.5 10.1 1.3 6.4 8.6 9.1 7.2 0.4 0.9 0.9 1 0.4 total mean dbar- 0.510 degree of freedom -n-1 Std deviaiton SpV(Ed-(zd)/n)/(n-1) - std error-Se So/Vn - test statistic(d-ud)/Se - 9.000 0.3900 0.123 4.1351 p value 0.0013

p value is less then 0.01 therefore we reject null hypothesis