Independent Two-Sample Pooled t-Test

Understand the independent pooled t-test under a common population variance. Combine within-group sums of squares, calculate standard errors, test nonzero contrasts and recover signed pooled Cohen’s d. Diagnose incorrect weighting, grand-mean pooling, pairing errors and assumption-sensitive conclusions. Prerequisites: Welch comparisons, sample variances and standardized effects. Includes single-select and multiselect practice with worked solutions and explanations of distractors.

References: 1.3.5.3 Independent t statistics, pooled variance, effective degrees of freedom and paired design, Standardized mean differences and within-subject designs, equations for d and difference SD.