Topic: Two-Sample t Inference

Why Unequal Variances Matter

Welch’s Standard Error for Two Means

Welch Confidence Intervals for a Mean Difference

Variance of a Difference Between Independent Sample Means

Unequal Sample Sizes Under Unequal Variances

Turning Software Output Into a Statistical Conclusion

The Welch T Statistic and Its Reference Distribution

The Pooled Two-Sample T Procedure

The Link Between Two-Sample Tests and Confidence Intervals

Satterthwaite Degrees of Freedom