Z Test Vs T Test. The t test is used to compare the mean of two given groups. Calculating the p value in a t test for a mean.
The t test can be understood as a statistical test which is used to compare and analyse whether the means of the two. A z test is a statistical test to help determine the probability that new data will be near the point. 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.
The t test is based on student s t distribution.
If you know the populations standard deviation you may use a z test. Calculating the test statistic in a t test for a mean. The z score and t score tables themselves have different numbers in response to the fact that you can t have as much confidence in the data with a smaller sample size. A t test is used when parameters like the standard deviation of the population are not known.
