A marketing research firm wishes to compare the prices charged by two supermarket chains-Miller's and Albert's. The research firm, using a standardized one-week shopping plan (grocery list), makes identical purchases at 10 of each chain's stores. The stores for each chain are randomly selected, and all purchases are made during a single week. It is found that the mean and the standard deviation of the shopping expenses at the 10 Miller's stores are X_1 = $ 121.92 and s_1 = 1.40. It is also a found that the mean and the standard deviation of the shopping expenses at the 10 Albert's stores are X_2 = $114.81 and s_2= 1.84. Assuming normality, test to see if the corresponding population standard deviations differ by setting a equal to .05. Is it reasonable to use the equal variances procedure to compare population means?
Calculate the value of the test statistic. (Do not round intermediate calculations. Round your answer to 2 decimal places.)
Calculate the critical value. (Round your answer to 2 decimal places.)