# Overview for Paired t

Use Paired t to do the following:
• Determine whether the mean of the differences between two paired samples differs from 0 (or a target value).
• Calculate a range of values that is likely to include the population mean of the differences.

The paired t-test is useful for analyzing the same set of items that were measured under two different conditions, differences in measurements made on the same subject before and after a treatment, or differences between two treatments given to the same subject.

For example, the manager of a fitness facility uses a paired t-test to determine whether a group of participants improved their fitness after an 8-week program. If there is a difference in fitness measurements before and after the program, the manager can use the confidence interval to determine whether the difference is practically significant.

## Where to find this analysis

To perform a paired t-test, choose Stat > Basic Statistics > Paired t.

## When to use an alternate analysis

If you have two samples of independent observations, use 2-Sample t instead. For more information, go to How are dependent and independent samples different?.