# When is Welch's t-test used?

Nov 24, 2017

A Welch's t-test is a variation of the Student's t-test that is used when the two samples have unequal variances.

#### Explanation:

A Welch's t-test is a variation of the Student's t-test that is used when the two samples have unequal variances. With a typical Student's t-test, one of the underlying assumptions that needs to be met is that both samples you're testing have equal variances. If you suspect this isn't the case, you use the Welch's t-test.