Question: Question 2:

Miami has one of the busiest ports on the eastern seaboard. Baltimore is a similarly busy port. In the associated data file are tons of cargo per day handled in each of these ports for a randomly selected number of days. Data are in thousands of tons.

a. Compute the sample mean and sample standard deviation for each airport. Discuss the results.

b. Calculate the point estimate for the difference between the two populations. Provide an intuitive interpretation of this value. Based on just this calculation, which port do you believe handles more tonnage on a typical day? Explain why point estimates are not sufficient for inference.

c. Develop a 95% confidence interval of the difference between the daily population means for the two seaports. Make sure you define your terms, and make explicit any assumptions you are making in the process of interval estimation. Provide an interpretation of the estimated CI interval.