ACNielsen is a New York-based leading global provider of marketing research information services, analytical systems and tools, and professional client service. A recent issue of its magazine (Todd Hale, "Winning Retail Strategies Start with High Value Consumers," Consumer Insight, Spring 2005) addressed, in part, consumers' attitudes toself-checkout lines. Of the 17,346 EDLP (every day low price) shoppers, only 3,470 indicated an interest in this service. If Wal-Mart's CEO, Lee Scott, had decided not to install self-checkout lines unless consumer interest was more than 17.5%, would he order the installation?
a. Determine if the sample size for the test indicated is large enough to warrant approximating the sample proportion's distribution with a normal distribution.
b. Use a significance level of 0.05 and the p-value approach to answer the question put forward above.