T test with unequal variances

1 · John Cook · Dec. 1, 2021, 7 p.m.
The test statistic in the t-test does not exactly follow a Student t distribution except under ideal conditions. If you’re comparing data from two normally distributed populations to see whether they have the same mean, the test statistic for the two-sample t-test does not have a t distribution unless the two populations have equal variance. […] The post T test with unequal variances first appeared on John D. Cook....