Power & Sample Size Calculator

*using the 2-Sample T-test method

Use this test method to:

- Determine whether the means of two independent groups (populations) differ.
- Calculate a range of values that is likely to include the difference between the population means.

Calculations are based on formulas for the 2-Sample T-test. To perform a 2-Sample T-test, the two populations must be independent; in other words, the observations from the first sample must not have any bearing on the observations from the second sample. If you have questions or problems you can contact Statistical Solutions via E-mail by clicking the following link. Contact Us

2-Sample T-test calculates a confidence interval and does a hypothesis test of the difference between two population means when standard deviations are unknown and samples are drawn independently from each other. This procedure is based on the t-distribution, and for small samples it works best if the data were drawn from distributions that are normal or close to normal. You can have increasing confidence in the results as the sample sizes increase.

*To use this page, your browser must recognize JavaScript.