A sportswriter wants to know how strongly Indianapolis, Indiana residents support the local minor league baseball team, the Indianapolis Indians. He stands outside the stadium before a game and interviews the first 30 people who enter the stadium. Suppose that the newspaper asks you to comment on the approach taken by this sportswriter in performing the survey. How would you respond?

Provide an example of when you might want to take a stratified random sample instead of a simple random sample, and explain the advantages of a stratified sample.

What is the difference between a standard deviation and a standard error? Be precise.

Explain as precisely as possible what the central limit theorem says about averages.

A local fast-food restaurant manager is interested in improving the service provided to customers who use the restaurant's drive-up window. As the first step in this process, the manager asks his assistant to record the time it takes to serve many customers at the final window in the facility's drive-up system. The results are in the file P07_08.xlsx, which consists of nearly 1200 service times. For this problem, you can assume that the population is the data in this file.

Generate a simple random sample of size 30 from the data.

Calculate a point estimate of the population means from the sample selected in part a. What is the sampling error, that is, by how much does the sample mean differ from the population mean?

Calculate a good approximation for the standard error of the mean.

If you wanted to halve the standard error from part c, what approximate sample size would you need? Why is this only approximate?