A television network plans to predict the outcome of an election between Jacalyn Levin and Roberto Sanchez. They will do this with an exit poll on election day. They decide to use a random sample size for which the margin of error is 0.04 for 95% confidence intervals for population proportions.

(a) What sample size should they use?

(b) If the pollsters think that the election will be close, they might use a margin of error of 0.02.

How large should the sample size be?