Use the standard normal distribution or the t-distribution to construct a 95% confidence interval for the population mean. Justify your decision. If neither distribution can be used, explain why. Interpret the results. In a random sample of 13 mortgage institutions, the mean interest rate was 3.56% and the standard deviation was 0.37%. Assume the interest rates are normally distributed. Which distribution should be used to construct the confidence interval? O A. Use a t-distribution because it is a random sample, o is unknown, and the interest rates are normally distributed. O B. Use a normal distribution because the interest rates are normally distributed and o is known. O C. Use a normal distribution because n