# Compare groups means tutorial

Learn how to test for a difference between the means of 2 groups and estimate the size of the effect.

Twenty-one African-American men participated in an experiment to test whether increasing calcium intake reduces blood pressure. Ten of the men took a calcium supplement for 12 weeks while the remaining 11 men received a placebo. Researchers measured the blood pressure of each subject before and after the 12-week period. The experiment was double-blind.

In this tutorial you will perform the following tasks:

- Testing for a difference of means

Test the hypothesis that the means of the groups are equal. - Testing assumptions of the t-test

Test the assumptions of the statistical procedure. - Trying a different statistical test

Make a copy of the analysis and try a different statistical test.

- Tutorials
- Distribution tutorial
- Correlation / PCA tutorial
- Compare groups means tutorial
- Testing for a difference of means
- Testing assumptions of the t-test
- Trying a different statistical test
- Association in 2-way contingency tables tutorial
- Simple linear regression tutorial
- Bland-Altman method comparison tutorial
- Estimating the precision of a measurement procedure (CLSI EP05-A3)
- Evaluating the linearity of a measurement procedure (CLSI EP06-A)
- Verifying the precision of a measurement procedure against a performance claim and estimating the bias (CLSI EP15-A3)
- Pareto charts tutorial
- Process control charts tutorial
- Process capability tutorial

Version 6.15

Published 18-Apr-2023