Question

A marketing experiment is conducted to determine whether consumers can taste the difference between Coke and Pepsi soft drinks. Each person drinks from two unmarked cups and then tries to identify the cup containing Pepsi. If the test is conducted on many different random samples of size 200, and consumers have no ability to distinguish between the two brands (i.e., consumers are equally likely to identify Coke or Pepsi), a. what proportion of the samples will find between 45% and 60% of consumers identifying Pepsi? b. The Pepsi brand manager wishes to know if consumers prefer the taste of Pepsi to Coke. In one sample of size 200 the researcher found that 120 consumers stated a preference for Pepsi over Coke. Estimate the true proportion of consumers who prefer Pepsi (give a point estimate and also 95% confidence interval). c. What is the margin of error of the confidence interval in part b)? If the margin of error is set to be 0.06, what is the required sample size?

Answer 1