Hi, I trying to determine the best way to compute the power for a one-sample one-sided binomial test. Specifically I need to sample a population of individuals and ask whether a sample rate of 0% is compatable with a minimum threshold of 3% and how many samples are needed.
I have made use of power.prop.test but I am not sure if a) that is the correct (or best) function to use and b) if the output is quite right. Here is a sample run: > power.prop.test(p1=0, p2=0.03, sig.level=0.05, power=0.90, alt="one.sided") Two-sample comparison of proportions power calculation n = 279.3004 p1 = 0 p2 = 0.03 sig.level = 0.05 power = 0.9 alternative = one.sided NOTE: n is number in *each* group This is an attempt to test whether a sample of 0% occurrance is compatable with an a-priori probability of 3% at the specified significance levels. My questions are those above, and, as a followup whether the caveat about n being the number in each group means that I need to sample twice that number in a single group. I don't believe so but I want to be sure. Thanks in advance, Collin Lynch. ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.