Suppose that if a presidential election were held today, 53% of all voters would vote for Obama over McCain. (You can substitute the names of the current presidential candidates.) This problem shows that even if there are 100 million voters, a sample of several thousand is enough to determine the outcome, even in a fairly close election.
a. If 1500 voters are sampled randomly, what is the probability that the sample will indicate (correctly) that Obama is preferred to McCain?
b. If 6000 voters are sampled randomly, what is the probability that the sample will indicate (correctly) that Obama is preferred to McCain?