A marketing research firm wishes to estimate the percent of homeowners who are dissatisfied with their present homeowner's insurance policy. A simple random sample of 400 homeowners led to 80 who were dissatisfied with their homeowner's insurance policy.
a. Compute the 95% confidence interval for the percent of homeowners who are dissatisfied with their homeowner's insurance policy.
b. Interpret this confidence interval.
c. How large a sample size will need to be selected if we wish to have a 95% confidence interval that is accurate to within 1%.