14 Comparing means among two groups

Tutorial learning objectives

• Learn about paired and two-sample study designs for comparing the mean of a numeric response variable among two categories of a categorical variable (i.e. two groups)
• Learn about the paired t-test for testing a hypothesis about the difference between means in a paired design (\(d\))
• Learn about the two-sample t-test for testing a hypothesis about the difference between two population means (\(\mu_1 - \mu_2\))
• Learn the assumptions of the paired and two-sample t-tests
• Learn how to calculate an exact confidence interval for the difference between two means
• Learn the confidence interval approach for testing the plausibility of a hypothesized value for \(\mu_1 - \mu_2\)