1, Use the standard normal distribution or thet-distribution to construct a 95% confidence interval for the population mean. Justify your decision. If neither distribution can beused, explain why. Interpret the results.

In a random sample of 14 mortgageinstitutions, the mean interest rate was 3.43% and the standard deviation was 0.38%. Assume the interest rates are normally distributed.

A. The 95% confidence interval is (nothing nothing).

(Round to two decimal places asneeded.)

2,Use the standard normal distribution or thet-distribution to construct a 90% confidence interval for the population mean. Justify your decision. If neither distribution can beused, explain why. Interpret the results.

In a random sample of 49 people, the mean body mass index(BMI) was 27.8 and the standard deviation was 6.06.

A. The 90% confidence interval is(nothing,nothing).

(Round to two decimal places asneeded.)

B.

Neither distribution can be used to construct the confidence interval.

3, In a random sample of seven people, the mean driving distance to work was 18.1 miles and the standard deviation was 5.6 miles. Assume the population is normally distributed and use thet-distribution to find the margin of error and construct a 99% confidence interval for the population mean . Interpret the results.

Identify the margin of error.( )miles

(Round to one decimal place asneeded.)

Construct a 95% confidence interval for the population mean. ( )

(Round to one decimal place asneeded.)

Interpret the results. Select the correct choice below and fill in the answer box to complete your' ;'choice.

(Type' an integer or a decimal. Do notround.)

A. It can be said that % of the population has a driving distance to work(in miles) that is between theinterval's endpoints.

B. With %confidence, it can be said that the population mean driving distance to work(in miles) is between theinterval's endpoints.

C. With % confidence, it can be said that most driving distances to work(in miles) in the population are between theinterval's endpoints.

D. % of all random samples of six people from the population will have a mean driving distance to work(in miles) that is between theinterval's endpoints.

4, Construct the indicated confidence interval for the population mean using thet-distribution. Assume the population is normally distributed.

c=0.99, x=13.2, s=0.68, n=18,

(Round to one decimal place asneeded.)