Question: One sample has n = 4 scores with SS = 100 and a second sample has n = 8 with SS = 140.

a. Calculate the pooled variance for the two samples.

b. Calculate the estimated standard error for the sample mean difference.

c. If the sample mean difference is 6 points, is this enough to reject the null hypothesis for a two-tailed test with α = .05?

d. If the sample mean difference is 9 points, is this enough to reject the null hypothesis for a two-tailed test with α = .05?