Welch two sample t test

1. What does a Welch two-sample t-test tell you?
2. What is the difference between t-test and Welch test?
3. What is the difference between Welch two-sample t-test and paired t-test?

What does a Welch two-sample t-test tell you?

What is Welch's t-test? Welch's t-test also known as unequal variances t-test is used when you want to test whether the means of two population are equal. This test is generally applied when the there is a difference between the variations of two populations and also when their sample sizes are unequal.

What is the difference between t-test and Welch test?

The most important difference between Student's t-test and Welch's t-test, and indeed the main reason Welch's t-test was developed, is when both the variances and the sample sizes differ between groups, the t-value, degrees of freedom, and p-value all differ between Student's t-test and Welch's t-test.

What is the difference between Welch two-sample t-test and paired t-test?

Two-sample t-test is used when the data of two samples are statistically independent, while the paired t-test is used when data is in the form of matched pairs.