A news reporter wants to survey voters about their candidate preferences in an upcoming national election.In order to be 95 percent confident of her results,and have only a 3 percent margin of error,she should make sure the sample has at least _____ individuals.

Question

Quizplus · Accepted Answer

The sample size should be calculated using the formula n = (z^2 * p * q) / E^2, where z is the z-score for the level of confidence (1.96 for 95% confidence), p is the estimated proportion of voters with the preferred candidate, q is 1-p, and E is the margin of error (0.03 in this case). Since we don't know the estimated proportion, we can assume a conservative value of 0.5 to get the maximum possible sample size. Plugging in the values, we get n = (1.96^2 * 0.5 * 0.5) / 0.03^2, which is approximately 1,175.15. Therefore, the sample should have at least 1,200 individuals to ensure a 95% confidence level and a 3% margin of error. Choice A is too small, choice C is too large, and choice D is even larger than necessary.

A News Reporter Wants to Survey Voters About Their Candidate