32. In July 2001, the Harris Ad Track Research Service conducted a survey to evaluate the effectiveness of a major advertising campaign for Kodak cameras (USA Today, August 27, 2001). In a sample of 430 respondents, 163 thought the ads were very effective. In another sample of 285 respondents to other ad campaigns, 66 thought the ads were very effective.

a. Estimate the proportion of respondents who thought the Kodak ads were very effective and the proportion of respondents who felt the other ads were very effective.

b. Provide a 95% confidence interval for the difference in proportions.

c. On the basis of your results in part (b), do you believe the Kodak advertising campaign is more effective than most advertising campaigns?