Is the dealers mean significantly greater than the national

Question

In 2008, a small dealership leased 21 Subaru Outbacks on 2-year leases. When the cars were returned in 2010, the mileage was recorded (see below).

40,020 24,975 14,348 17,307 44,719 44,542 20,216 33,328 24,269 41,761 58,385 35,896 25,743 28,968 25,049 43,367 23,941 43,546 53,613 31,810 36,738

A) Is the dealer's mean significantly greater than the national average of 29,493 miles for 2-year leases? Using the 10 percent level of significance, choose the appropriate hypothesis.

a.H₀: μ ≤ 29,493 miles vs. H₁: μ > 29,493 miles, reject H₀ if t_calc > 1.3250b.H₀: μ ≥ 29,493 miles vs. H₁: μ > 29,493 miles, reject H₀ if t_calc > 1.3250c.H₀: μ ≤ 29,493 miles vs. H₁: μ < 29,493 miles, reject H₀ if t_calc > 1.3250d.H₁: μ ≤ 29,493 miles vs. H₀: μ > 29,493 miles, reject H₀ if t_calc > 1.3250

B) Calculate the test statistic.