Primarily sample size and whether the standard deviation is known or not.
Z-test is a statistical hypothesis test that follows a normal distribution while T-test follows a Student’s T-distribution.
A T-test is appropriate when you are handling small samples (n < 30) while a Z-test is appropriate when you are handling moderate to large samples (n > 30).
T-test is more adaptable than Z-test since Z-test will often require certain conditions to be reliable. Additionally, T-test has many methods that will suit any need.
T-tests are more commonly used than Z-tests.
Z-tests are preferred than T-tests when standard deviations are known.
Read more: Difference Between Z-test and T-test | Difference Between http://www.differencebetween.net/miscellaneous/difference-between-z-test-and-t-test/#ixzz4zbDXUQ8F
Impact of this question
Creative Commons License