The mean brain volume for a group of healthy adults is collected and the mean brain volume of adults diagnosed with obsessive-compulsive behavior is also obtained. The results are listed below. Test the claim that there is a difference between the two population means. Use a 0.01 significance level.
Control Group: n = 10 xbar = 0.45 s = 0.08
Obsessive-compulsive patients: n = 10 xbar = 0.34 s = 0.08
According to book, CI is -.01< u1-u2< .23
Please show how the above answer is reached, I have tried several ways and can't get those numbers.