You want to determine the percentage of Fortune 500 CEOs who think Indiana University (IU) deserves its current Business Week rating. You mail a questionnaire to all 500 CEOs and 100 respond. Exactly half of the respondents believe IU does deserve its ranking.
a. Find a 95% confidence interval for the fraction of Fortune 500 CEOs who believe IU deserves its ranking.
b. Suppose again that you want to estimate the fraction of Fortune 500 CEOs who believe IU deserves its ranking. Your goal is to have only a 5% chance of having your estimate be in error by more than 0.02. What size sample would you need to take?