I have a situation that is the opposite of the usual two-sample t-test for equal means: I'm trying to show that it's statistically unlikely that two samples are different.

Is there a statistical test that has the null hypothesis being that the two samples are unequal, and the alternate hypothesis being that the two samples are equal? The number of samples in these tests is small (5 samples each), so I need an equivalent to the t-test, not to the z-test.

Thank you for your help!