Discuss each of the following topics in class or review the topics on your own. Then write a brief but complete essay in which you summarize the main points. Please include formulas and graphs as appropriate.
1. What does it mean to say that we are going to use a sample to draw an inference about a population? Why is a random sample so important for this process? If we wanted a random sample of students in the cafeteria, why couldn’t we just take the students who order Diet Pepsi with their lunch? Comment on the statement, “A random sample is like a miniature population, whereas samples that are not random are likely to be biased.” Why would the students who order Diet Pepsi with lunch not be a random sample of students in the cafeteria?
2. In your own words, explain the differences among the following sampling techniques: simple random sample, stratified sample, systematic sample, cluster sample, multistage sample, and convenience sample. Describe situations in which each type might be useful.