Comparing two populations or treatments is one of the most common situations encountered in statistical practice.
These situations are referred to as two sample problems. The goal of inference is to compare the responses to two treatments or to compare the characteristics of two populations.
What is a two sample t-test?
A Two sample t-test is an inference test for comparison between 2 population means.
What are the differences between the t-test and z-test?
The difference is that for two sample t-tests, we do not know the means or standard deviations of the populations.
And for z-tests, we do know the population mean and standard deviations.
Before running a two sample t-test make sure these requirements are met:
- The samples are SRSs
- The populations are normally distributed
- The samples are independent of each other
- and the means and standard deviations for the populations are unknown.
Hypotheses
