Question: Brain VoluMeand Psychiatric Disorders. A study used 2-ray computed tomography (CT) to collect data on brain volumes for a group of patients with obsessive-compulsive disorders and a control group of healthy persons. Sample results (in mL) are given below for total brain volumes (based on data from “Neuroanatomical Abnormalities in Obsessive-Compulsive Disorder Detected with Quantitative X-Ray Computed Tomography.” By Luxenburg et al.)

a.) Construct a 95% confidence interval for the difference between the mean brain volume of obsessive-compulsive patients and the mean brain volume of healthy persons. Do not assume that the two populations have equal variances.

b.) Use a 0.05 significance level to test the claim that there is no difference between the mean for obsessive-compulsive patients and the mean for healthy persons. Do not assume that the two populations have equal variances.

c.) Based on the results from parts (a) and (b), does it appear that the total brain volume can be used as an indicator of obsessive-compulsive disorders?

Obsessive- Compulsive patients: n =10,`x = 1390.03, s =156.84

Control Group: n =10, `x = 1268.41, s =137.97