Marketing strategists would like to predict consumer response to new products and their accompanying promotional schemes. Consequently, studies that examine the differences between buyers and nonbuyers of a product are of interest. One classic study conducted was aimed at characterizing the purchasers and nonpurchasers of Crest toothpaste. The researchers demonstrated that both the mean household size (number of persons) and mean household income were significantly larger for purchasers than for nonpurchasers. A similar study utilized random sample size of 20 and yielded the age of the householder primarily responsible for buying toothpaste as shown: Purchasers: 34, 35, 23, 44, 52, 46, 28, 48, 28, 34, 33, 52, 41, 32, 34, 49, 50, 45, 29, 59 Nonpurchasers: 28, 22, 44, 33, 55, 63, 45, 31, 60, 54, 53, 58, 52, 52, 66, 35, 25, 48, 59, 61

a. Do the data present sufficient evidence to conclude there is a difference in the mean age of purchasers and nonpurchasers? Use alfa= 0,10.

b. What assumptions are necessary in order to test if there is a difference in the mean age of purchasers and nonpurchasers?

c. Find the observes significance level for the test and interpret its value.

d. Calculate and interpret a 90% CI for the difference between the mean ages of purchasers and nonpurchasers.