Z Test T Test. Z tests are a statistical way of testing a hypothesis when either. We know the population variance or.
We know the population variance or. We do not know the population variance but our sample size is large n 30. T test refers to a type of parametric test that is applied to identify how the means of two sets of data differ from one another when variance is not given.
Population mean is same as the sample mean.
We do not know the population variance but our sample size is large n 30. Population mean is not the same as the sample mean. The sample follows a gaussian distribution. Population mean is same as the sample mean.