Exemple number 17:

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 us In a random sample of 21 mortgage institutions, the mean interest rate was 3.63% and the standard deviation was 0.45%. 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 n