As in Exercise 17, you want to estimate the proportion of traditional college students on your campus who own their own car. However, from some research on other college campuses, you believe the proportion will be near 20%.
a) What sample size is needed if you wish to be 95% confident that your estimate is within 0.02 of the true proportion?
b) What sample size is needed if you wish to be 99% confident that your estimate is within 0.02 of the true proportion?
c) What sample size is needed if you wish to be 95% confident that your estimate is within 0.05 of the true proportion?