Confidence intervals for the difference between independent binomial proportions (x1/n1 - x2/n2): Online confidence interval calculator		Input data: x1:   x2: n1:    n2: Confidence level: % (2-sided) Include 'exact' methods? (takes longer)	Comparison of methods using a graphical approach and moving averages	Confidence intervals for Relative Risk, Odds Ratio, single proportion, and Poisson rate contrasts