Question

A population has standard deviation o = 17.3. Part 1 out of 2 How large a sample must be drawn so that a 80% confidence interval for u will have a margin of error equal to 1? Round up the answer to the nearest integer. (Round the critical value to no less than three decimal places.) is needed to be drawn in order to obtain a 80% confidence A sample size of interval with a margin of error equal to 1

Answer 1

Sample size = (Z$\alpha$/2 * $\sigma$ / E)²

= ( 1.2816 * 17.3/ 1)²

= 491.58

n = 492 (Rounded up to nearest integer)