# Differance between z-test and t-test

#### brew32

##### New member
Just wanted to be sure I captured all theinformation for the following question:

What is a fundamental difference between the z?test and the t?test for testing hypotheses about population means?

Using a z distribution is not effective with small sample sizes.The t-test should be used for small sample sizes and the z-test should be used for large sample sizes. If the t-test is used for large sample sizes, it should provide the same results as the z-test.

#### galactus

##### Super Moderator
Staff member
We normally use the t-test when the sample size is less than 30. Yes, as the sample size grows larger, the t-test appraoches the z-test.