Statistics Question

Question

A political candidate has asked you to conduct a poll to determine what percentage of people support her.

If the candidate only wants a 6% margin of error at a 99% confidence level, what size of sample is needed?

Give your answer in whole people.

Answer 1

Margin of error = z √ (pq/n)

z = 2.58 (because 99% confidence level)

assume p = q = 0.5 (given no better information)

So we want 0.06 = z √ (pq/n)

You know z, p, q, solve this for n