A home warranty company wants to determine if the average repair cost at West Coast Appliance Repair is less than at A Plus Appliance Repair. Two independent random samples reveal the following information: West Coast Appliance Repair A Plus Number of customers 40 50 Sample mean 250 260 Sample standard deviation 23 20 A. Select the appropriate inference procedure and verify conditions for using it. Develop a 95% confidence interval estimate for the difference between the average repair costs at two companies. B. Based on your answer to part (A), is there conclusive evidence to prove that the average repair cost at one company is greater than at the other? If yes, which company? Explain