One sample has n = 15 with SS = 1740, and a second sample has n = 15 with SS = 1620.

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 the alpha .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 the alpha .05 level?