For each of the following situations, state whether you’d use a chi-square goodness-of-fit test, a chi-square test of homogeneity, a chi-square test of independence, or some other statistical test.
a) Is the quality of a car affected by what day it was built? A car manufacturer examines a random sample of the warranty claims filed over the past two years to test whether defects are randomly distributed across days of the work week.
b) A researcher for the American Booksellers Association wants to know if retail sales/sq. ft. is related to serving coffee or snacks on the premises. She examines a database of 10,000 independently owned bookstores testing whether retail sales (dollars/sq. ft.) is related to whether or not the store has a coffee bar.
c) A researcher wants to find out whether education level (some high school, high school graduate, college graduate, advanced degree) is related to the type of transaction most likely to be conducted using the Internet (shopping, banking, travel reservations, auctions). He surveys 500 randomly chosen adults and performs a test.