196 for 95 confidence level p percentage picking a choice expressed as decimal. Z test formula computed by the Sample means minus population means divided by population standard deviation and sample size. Iterate on the initial estimate using critical values from the t table.
Assumptions of Central Limit Theorem.
Sample Size z2 p 1-p e2 1 z2 p 1-p e2 N N population size. C Confidence interval. 196 for 95 confidence level p percentage picking a choice expressed as decimal. The standard formula for sample size is.