Assignment:
Before/After Drug Effects Captopril is a drug designed to lower systolic blood pressure. When subjects were tested with this drug, their systolic blood pressure readings (in mm Hg) were measured before and after drug treatment, with the results given in the following table (based on data from "Essential Hypertension: Effect of an Oral Inhibitor of Angiotensin-Converting Enzyme," by MacGregor, et al., British Medical Journal, Vol. 2).
a. Use the sample data to construct a 99% confidence interval for the mean difference between the before and after readings.
b. Is there sufficient evidence to support the claim that captopril is effective in lowering systolic blood pressure?
|
Subject
|
A
|
B
|
C
|
D
|
E
|
F
|
G
|
H
|
I
|
J
|
K
|
L
|
|
Before
|
200
|
174
|
198
|
170
|
179
|
182
|
193
|
209
|
185
|
155
|
169
|
210
|
|
After
|
191
|
170
|
177
|
167
|
159
|
151
|
176
|
183
|
159
|
145
|
146
|
177
|