can you help me find sp

video: Hypothesis Testing for the Two-Sample Case Part 2 A$ women: X1 = 7.8 men: X2 = 6.7 $1 = 0.23 $2 = 0.16 N1 = 46 N2 = 42 sp: the pooled estimator of the sampling distribution of differences in means N1S2 + N252 N1 + N2 Sp N1 + N2 - 2 N1N2 Notes: 1. so is called a "pooled" estimator because it uses information from both populations. The formula for sp shows that it is a weighted average of the two samples. 2. Specifically, we need to know the size (N) and variance (s?) of sample from each population. 3. This is the reason for the "extra" assumption in Step 1