Inference App

[mcjtom]

Would anyone know how the confidence interval/critical values on proportions (i.e. test type: 1 p and p1-p2) is calculated (i.e. what's the distribution and formulas being used)?

It looks to me that the sample proportion's bionomial distribution is simply approximated as normal, regardless of the sample size or proportion value being close to 0 or 1. If that's the case, it may at least deserve some warning on screen or in Help (e.g. http://en.wikipedia.org/wiki/Binomial_pr...e_interval).

But is it true?