A rental car company wants to investigate whether the type of car rented affects the length of the rental period. An experiment is run for one week at a particular location, and 7 rental contracts are selected at random for each car type. The results are shown in the following table. Type of Observations (Days) Car 1 3 5 3 7 6 5 2 1 3 4 7 5 6 3 4 1 3 5 7 1 4 3 5 7 5 10 3 4 (a) A partial computer ANOVA output is shown below. Fill in the blanks. Sum of Squares Mean Square Computed f Source of Variation Degrees of Freedom Treatments 14.68 ? ? Error ? ? Total 122.11 ? (b) State the hypotheses to test whether the type of car rented affects the length of the rental contract and use appropriate testing procedure to test your hypotheses. (c) Based on the observed data, the sample variance of the length of the rental contract for each type of car can be summarized as follow: S = 2.619048, S3 = 4.904762, S = 4.142857, S2 = 6.238095 Verify that whether the variances are homogeneous. State the hypothesis and test your hypothesis with appropriate method. (Assume a = 0.05) Is the ANOVA test appropriate? Why? (d) Use Tukey's procedure with a = 0.05 to make comparisons between pairs of means. Are there any pairs of means showing significantly different? 332 2