America's young people are heavy Internet users; 87% of Americans ages 12 to 17 are Internet users (The Cincinnati Enquirer, February 7, 2006). MySpace was voted the most popular Web site by 9% in a sample survey of Internet users in this age group. Suppose 1,400 youths participated in the survey. What is the margin of error, and what is the interval estimate of the population proportion for which MySpace is the most popular Web site? Use a 95% confidence level.