10.10 Comparing marketing commercials Two TV commercials are developed for marketing a new product. A volunteer test sample of 200 people is randomly split into two groups of 100 each. In a controlled setting, Group A watches commercial A and Group B watches commercial B. In Group A, 25 say they would buy the product. In group B, 20 say they would buy the product. The marketing manager who devised this experiment concludes that commercial A is better. Is this conclusion justified? Analyze the data. If you prefer, use software (such as MINITAB or a web app) for which you can enter summary counts.

a. Show all steps of your analysis (perhaps including an appropriate graph) and check assumptions.

b. Comment on the manager’s conclusion and indicate limitations of the experiment.