A loan officer at a bank wishes to compare the mortgage rates charged at banks in Texas with the mortgage rates of Texas savings and loans. Two independent random samples of bank mortgage rates and savings and loan mortgage rates in Texas are obtained with the following results:

Because both samples are small, the bank officer is uncertain about the shape of the distributions of bank and savings and loan mortgage rates. Therefore, the Wilcoxon rank sum test will be used to compare the two types of mortgage rates.
a. Let D1 be the distribution of bank mortgage rates and let D2, be the distribution of savings and loan mortgage rates. Carry out the Wilcoxon rank sum test to determine whether D1 and D2 are identical versus the alternative that Di is shifted to the right or left of D2. Use α = .05.
b. Carry out the Wilcoxon rank sum test to determine whether Dl is shifted to the right of D2. Use α = .025. What do you conclude?

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Bank Rates: 9.25 7.25 8.50 8.25 9.50 6.75 9.00 9.00 8.00 7.75 7.507.00 8.25 6.50 9.50 S&L Rates: 7.10