The formula for calculating the minimum sample size needed to estimate the population proportion with a margin of error of 0.05 or less at 95% confidence is:
n = (z^2 * p * (1-p)) / (e^2)
where:
n = sample size
z = z-score (1.96 for 95% confidence)
p = estimated population proportion
e = margin of error (0.05)
Therefore, substituting the values into the formula, we get:
n = (1.96^2 * 0.5 * (1-0.5)) / (0.05^2)
n = 58
1. We are interested in conducting a study in order to determine what percentage of voters of a state would vote for the incumbent governor. What is the minimum size sample needed to estimate the population proportion with a margin of error of 0.05 or less at 95% confidence?
Answer is 58 but I don't know how to show work.
Thank you
1 answer