One sample has n = 15 with SS = 1570, and a second sample has n = 15 with SS - 1650. a. Find the pooled variance for the two samples. b Compute the estimated standard error for the sample mean differences (i.e. for the two groups). C. If the sample mean difference (i.e. M1 - M2) is 8 points, is this enough to indicate a significant difference for a two-tailed test at a = .05 level? d. If the sample mean difference (i.e. M1 - M2) is 12 points, is this enough to indicate a significant difference for a two-tailed test at a = .05 level