Vermont-based Green Mountain Coffee Roasters dominates the market for single-serve coffee in the United States,with its subsidiary Keurig accounting for approximately 70% of sales ("Rivals Try to Loosen Keurig's Grip on Single-Serve Coffee Market," Chicago Tribune,February 26,2011).But Keurig's patent on K-cups,the plastic pods used to brew the coffee,is expected to expire in 2012,allowing other companies to better compete.Suppose a potential competitor has been conducting blind taste tests on its blend and finds that 47% of consumers strongly prefer its French Roast to that of Green Mountain Coffee Roasters.After tweaking its recipe,the competitor conducts a test with 144 tasters,of which 72 prefer its blend.The competitor claims that its new blend is preferred by more than 47% of consumers to Green Mountain Coffee Roasters' French Roast.Which of the following should be used to develop the null and alternative hypotheses to test this claim?

Question

Quizplus · Accepted Answer

Choice C presents the appropriate language for developing null and alternative hypotheses to test the claim. It sets up a two-sided test to determine if the proportion of consumers who prefer the competitor's blend is different than the proportion who prefer Green Mountain Coffee Roasters' French Roast. The use of a two-sided test is appropriate since the claim is that the competitor's blend is preferred "more than" Green Mountain's French Roast, which could mean either a higher or lower proportion of consumers. Therefore, the null hypothesis is that the proportion of consumers who prefer the competitor's blend is equal to 47%, and the alternative hypothesis is that the proportion is not equal to 47%.

Vermont-Based Green Mountain Coffee Roasters Dominates the Market for Single-Serve