A regional package delivery company is considering changing from full-size vans to minivans. The company sampled minivans from each of the three manufacturers. The number sampled represents the number the manufacturer was able to provide for the test. Each minivan was driven for 5,000 miles and the operating cost per mile was computed. The operating costs, in cents per mile, for the 12 are provided below: Mini 1 Mini 2 Mini 3 13.3 12.4 13.9 14.3 13.4 15.5 13.6 13.1 15.2 12.8 14.2 14.5 Perform an analysis of variance on these data. Assume a level of significance of 0.05. Do the experimental data provide evidence that the average operating costs per mile for the three types of minivans are different? State the null and alternative hypotheses and the decision rule. Report the results of the post hoc analysis. What conclusions should be reached concerning which type of car the delivery company should adopt? Justify your answer.