Two separate samples, each with n 5 9 individuals, receive different treatments. After treatment, the first sample has SS 5 546 and the second has SS 5 606.

a. Find the pooled variance for the two samples.

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

c. If the sample mean difference is 8 points, is this enough to reject the null hypothesis and conclude that there is a significant difference for a two-tailed test at the .05 level?