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 Ha.
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. |

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