Hi Lena,
We can use the samsizepwr command for the respective testtypes:
- 'z' — z-test for normally distributed data with known standard deviation.
- 't' — t-test for normally distributed data with unknown standard deviation.
- 't2' — Two-sample pooled t-test for normally distributed data with unknown standard deviation and equal variances.
- 'var' — Chi-square test of variance for normally distributed data.
- 'p' — Test of the p parameter (success probability) for a binomial distribution. The 'p' test is a discrete test for which increasing the sample size does not always increase the power. For n values larger than 200, there may exist values smaller than the returned n value that also produce the specified power.
For more information you can refer the link - Sample size and power of test
