Statistics and Probability questions assignment

Question 1:  In a random sample of 29 people, the mean commute time to work was 32.6 minutes and the standard deviation was 7.1 minutes. Assume the population is normally distributed and use a t-distribution to construct an 80% confidence interval for the population mean µ. What is the margin of error of µ? Interpret the results.

Question 2: Construct the indicated confidence interval for the population mean µ using the t-distribution.    c=0.99, x=14.9, s= 2.0, n=5

Question 3: A publisher wants to estimate the mean length of time (in minutes) all adults spend reading newspapers. To determine the estimate, the publisher takes a random sample of 15 people and obtains the results below. From past studies, the publisher assumes σ is 2.1 minutes and that the population of times is normally distributed.

9    7    10    11    8    11    9    12    11    10    12    6    6    12    12

Construct the 90% and 99% confidence intervals for the population mean. Which interval is wider? If convenient, use technology to construct the confidence intervals.