Question

a randomized comparative experiment tests whether a cholesterol medication lowers the overall blood pressure for male patients. the control group has ten male patients and the treatment group, which receives the medication, has 10 male patients. all patients started with a cholesterol level of 245 mg/dl.

	cholesterol in mg/dl
treatment	230	225	220	218	224	240	232	221	235	224

what is the difference in the treatment mean and control mean? round to the nearest tenth.

a. -18
b. -9.2
c. -10
d. -24.7

Explanation:

Step1: Calculate control - group mean

$\bar{x}_{control}=\frac{241 + 243+242+245+250+248+246+245+242+247}{10}=\frac{2459}{10}=245.9$

Step2: Calculate treatment - group mean

$\bar{x}_{treatment}=\frac{230 + 225+220+218+224+240+232+221+235+224}{10}=\frac{2299}{10}=229.9$

Step3: Calculate the difference

$\bar{x}_{treatment}-\bar{x}_{control}=229.9 - 245.9=-16$

Answer:

None of the provided options (a. -18, b. -9.2, c. -10, d. -24.7) are correct. The correct difference is -16.