This calculator runs a two sample independent proportions test for given sample data and specified null and alternative hypotheses. Enter the data in the fields below. For each sample enter the total number of scores (\(n_1\) and \(n_2\)) and the number of scores that have the trait of interest (\(f_1\) and \(f_2\)).

Enter a value for the null hypothesis. This value should indicate the absence of an effect in your data. It must be between the values 0 and 1. Indicate whether your alternative hypothesis involves one-tail or two-tails. If it is a one-tailed test, then you need to indicate whether it is a positive (right tail) test or a negative (left tail) test.

Enter an \(\alpha\) value for the hypothesis test. This is the Type I error rate for your hypothesis test. It also determines the confidence level \(100 \times (1-\alpha)\) for a confidence interval. The confidence interval is based on the normal distribution, which is an approximation.

Press the Run Test button and a table summarizing the computations and conclusions will appear below.