In 2008, a small dealership leased 21 Suburu Outbacks on 2-year leases. When the cars were returned at the end of the lease, the mileage was recorded. 40,004 24,942 14,344 17,377 44,728 44,507 20,224
33,372 24,277 41,787 58,314 35,830 25,723 28,964
25,078 43,337 23,941 43,588 53,617 31,876 36,717
(a) Is the dealer's mean significantly greater than the national average of 29,452 miles for 2-year leases? Using the 10 percent level of significance, choose the appropriate hypothesis.
1. H0: μ ≤ 29,452 miles vs. H1: μ > 29,452 miles, reject H0 if tcalc > 1.3250
2. H0: μ ≥ 29,452 miles vs. H1: μ > 29,452 miles, reject H0 if tcalc > 1.3250
3. H0: μ ≤ 29,452 miles vs. H1: μ < 29,452 miles, reject H0 if tcalc > 1.3250
4. H1: μ ≤ 29,452 miles vs. H0: μ > 29,452 miles, reject H0 if tcalc > 1.3250
(b) Calculate the test statistic.