Types of samples and their distributions

You have been assigned to determine whether more people prefer Coke or Pepsi. Assume that roughly half the population prefers Coke and half prefers Pepsi. How large a sample do you need to take to ensure that you can estimate, with 90% confidence, the proportion of people preferring Coke to within 5% of the actual value? Show all of your work. In your Excel spreadsheet, Identify the sample size. Utilize the support tool of Excel. Present any equations utilized.