Question

A population has standard deviation ơ-17.7. Part 1 out of 2 How large a sample must be drawn so that a 99.9% confidence interval for μ will have a margin of error equal to 1.3? Round up the answer to the nearest integer. (Round the critical value to no less than three decimal places.) A sample size of D is needed to be drawn in order to obtain a 99.9% confidence interval with a margin of error equal to 1.3 CHECK NEXT

Answer 1

Sample size = Z²$\alpha$/2 * $\sigma ^{2}$ / E²

= 3.2905² * 17.7² / 1.3²

= 2007.17

Sample size n = 2008 (rounded up to nearest integer)