This web calculator conducts a z-test for the difference between two populations' proportions. The calculator includes an explanation of inputs and outputs. This web calculator conducts a z-test for ...

This applet allows users to specify a hypothesized population proportion, sample proportion and sample size as well as an alternative hypothesis and significance level. After changing the values, the ...

Power analyses and sample size calculations are important parts of many research projects. Often, before data are even collected, it is necessary to calculate and justify the required sample size for ...