1) The International Air Transport Association surveys business travelers to develop quality ratings for transatlantic gateway airports. The maximum possible rating is 10. Suppose a simple random sample of 50 business travelers is selected and each traveler is asked to provide a rating for the Miami International Airport. The ratings obtained from the sample of 50 business travelers follow.

8 8 4 0 5 5 5 4 4 4 4 3 1 0

6 1 0 1 0 0 8 5 4 3 2 4 7 8 9

1 0 8 4 5 5 4 4 3 8 9 9 5 3

9 8 8 5 1 0 4 1 0 5 5 3 3

Develop a 95% confidence interval estimate of the population mean rating for Miami. Round your answers to two decimal places.

( , )

2)

Annual starting salaries for college graduates with degrees in business administration are generally expected to be between $20,000 and $40,000. Assume that a 95% confidence interval estimate of the population mean annual starting salary is desired.

a. What is the planning value for the population standard deviation?

b. How large a sample should be taken if the desired margin of error is $300? Round your answer to the next whole number.

$150?