Is there a difference in the prices if you shop as an impulsive shopper, if you shop as a savvy shopper, if you shop at a warehouse club such as Costco, or if you purchase store brands? To investigate this, a random sample of 10 purchases was selected, and the prices were compared. (Data extracted from "Shop Smart and Save Big," Consumer Reports,
May 2009, p. 17.) The prices for the products are stored in Shopping2.
a. At the 0.05 level of significance, is there evidence of a difference between the mean price of an impulsive shopper, a savvy shopper, a shopper at a warehouse club such as Costco, or a purchaser of store brands?
b. What assumptions are necessary to perform this test?
c. If appropriate, use the Tukey procedure to determine which types of shopping differ. (Use a = 0.05.)
d. Do you think that there was a significant block effect in this experiment? Explain.