Use the standard normal distribution or the t-distribution to construct a 99% confidence interval for the population mean. Justify your decision. If neither distribution can be used, explain why. Interp the results. In a random sample of 13 mortgage institutions, the mean interest rate was 3.68% and the standard deviation was 0.33%. Assume the interest rates are normally distributed. Which distribution should be used to construct the confidence interval? OA. Use a t-distribution because the interest rates are normally distributed and is known. OB. Use a normal distribution because n<30 and the interest rates are normally distributed. OC. Use a normal distribution because the interest rates are normally distributed and is known. D. Use a t-distribution because it is a random sample, a is unknown, and the interest rates are normally distributed. E. Cannot use the standard normal distribution or the t-distribution because a is unknown, n<30, and the interest rates are not normally distributed. Select the correct choice below and, if necessary, fill in any answer boxes to complete your choice. OA. The 99% confidence interval is (). (Round to two decimal places as needed.) OB. Neither distribution can be used to construct the confidence interval. Interpret the results. Choose the correct answer below. OA. With 99% confidence, it can be said that the population mean interest rate is between the bounds of the confidence interval. OB. It can be said that 99% of institutions have an interest rate between the bounds of the confidence interval. OC. If a large sample of institutions are taken approximately 99% of them will have an interest rate between the bounds of the confidence interval.