14. A study used X-ray computed tomography (CT) to collect data on brain volumes for a group of patients treated with certain medication and a control group of persons without the medication. Sample results (in mL.) are given below for total brain volumes.

Treated patients: n = 10, mean = 1510.03, s = 150.84 Control group: n = 10, mean = 1268.41, s = 137.97

a. Use a 0.05 significance level to test the claim that the mean volume for patients with the treatment and the mean for persons without the treatment is the same. Show or explain your thinking.