1) A media rating company that publishes television ratings uses a random sample of 1600 households and finds that 20% watched a particular show in a given week. What is the approximate margin of error?

2) Polls showed that the two main candidates in the 2004 presidential election were nearly tied on the day before the election. To predict the winner, a newspaper would like to have a poll which has margin of error of 5%. Roughly how large a sample would be needed for such a poll? (Hint: since candidates are nearly tied, each has roughly 50% of the vote.)