T-distributions are most likely used to compare two process means. It is a hypothesis test of means.

See Paired T or Student’s T.

## Video on How to Create a 1 Sample T Test in MiniTab

Good example of two sample T tests here.

- http://www.cliffsnotes.com/math/statistics/univariate-inferential-tests/one-sample-t-test (One sample T test)
- http://www.cliffsnotes.com/math/statistics/univariate-inferential-tests/two-sample-t-test-for-comparing-two-means (Two sample T test for comparing two means / DF for separate s: the smaller of n 1– 1 and n 2– 1 DF for pooled s:
*df*=*n*1+*n*2– 2)