In a Yankelovich Partners poll of 1000 adults USA Today 20 A

In a Yankelovich Partners poll of 1000 adults (USA Today, 20 April 1998), 45% reported that they believe in \"faith healing\". Based on this survey, 95% confidence interval for the proportion in the population who believe about 42% to 48%. Would a 99% confidence interval for this same proportion be wider or narrower than the interval (42%, 48%)? Explain.

Solution

Higher confidence level gives wider confidence interval