comparing proportions

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comparing proportions

 Hi, I have a dataset that has 2 groups of samples. For each sample, then response measured is the number of success (no.success) obatined with the number of trials (no.trials). So a porportion of success (prpop.success) can be computed as no.success/no.trials. Now the objective is to test if there is a statistical significant difference in the proportion of success between the 2 groups of samples (say n1=20, n2=30). I can think of 2 ways to do the test: 1. regular t test based on the variable prop.success 2. Mann-Whitney test based on the variable prop.success 2. do a binomial regression as:     fit<-glm(cbind(no.success,no.trials-no.success) ~ group, data=data,          family=binomial)     anova(fit, test='Chisq') My questions is: 1. Is t test appropriate for comparing 2 groups of proportions? 2. how about Mann-Whitney non-parametric test? 3. Among the 3, which technique is more appropriate? 4. any other technique you can suggest? Thank you, John               [[alternative HTML version deleted]] ______________________________________________ [hidden email] mailing list https://stat.ethz.ch/mailman/listinfo/r-helpPLEASE do read the posting guide http://www.R-project.org/posting-guide.htmland provide commented, minimal, self-contained, reproducible code.
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