A manufacturer claims that the mean operating cost per mile of its minivans is less than that of its leading competitor. You conduct a study using 34 randomly selected minivans from the manufacturer and 38 from the leading competitor. The results are shown below. At α = 0.10, can you support the manufacturer’s claim? Assume the population variances are equal.

Sample Statistics for Minivan Operating Costs

a. Identify the claim and state H₀ and H_a.

b. Identify the level of significance α and the degrees of freedom.

c. Find the critical value and identify the rejection region.

d. Find the standardized test statistic t. Sketch a graph.

e. Decide whether to reject the null hypothesis.

f. Interpret the decision in the context of the original claim.

Transcribed Image Text:

Manufacturer Competitor $0.56/mi x2 $0.58/mi 1$0.08/mi2$0.07/mi 34 2 38