Final answer:
A T-test for dependent samples should be used to determine if the average heart rate changed before and after meditation, as it compares the means of the same individuals measured twice.
Step-by-step explanation:
To determine whether the average heart rate changed from before to after meditation in a sample of 50 people, the appropriate statistical test to use is a T-test for dependent samples. This is because the same individuals are being measured twice, before and after meditation, which makes the samples dependent. The dependent samples T-test compares the means of two related groups to detect any differences in the population averages. It is also known as the paired sample T-test or the repeated-measures T-test.