This web calculator conducts a pooled-variance t-test for a difference between two populations' means when standard deviations are unknown and equal. The calculator includes a video definition, an ...

The two-sample t-test is one of the most commonly used hypothesis tests in Six Sigma work. It is applied to compare the average difference between two groups. You use it to determine if the ...

A two-sample z-test for population means compares two population means ... The calculator includes a video definition, an explanation of the formula and practice examples.