Determine the margin of error for a 95% confidence interval for the difference between population means for each of the following (assume equal population variances):
a. nx = 10 s2x = 6 x-bar = 200
ny = 16 s2y = 10 y-bar = 160
b. nx = 5 s2x = 6 x-bar = 200
ny = 8 s2y = 10 y-bar = 160
c. The sample sizes in part a are double the sample sizes in part b. Comment on your answers to part a compared to your answers to part b.