For the independent-measures t test, which of the following describes the pooled variance (whose symbol is )? a weighted average of the two sample variances (weighted by the sample sizes) the variance across all the data values when both samples are pooled together an estimate of the standard distance between the difference in sample means (m₁ – m₂) and the difference in the corresponding population means (μ₁ – μ₂) the difference between the standard deviations of the two samples