For example, a university financial aid officer wants to determine whether male or female students are more likely to get a job in the summer. Before collecting the data for a 2 proportions test, the officer uses a power and sample size calculation to determine how small of a difference the test can detect with the desired sample size and power.
To perform a power and sample size calculation for a 2 proportions test, choose
.If your data contain counts, such as the number of defects per unit, use Power and Sample Size for 2-Sample Poisson Rate. For more information on data types, go to Data types you can analyze with a hypothesis test.