Question

Question 10 3 pts Captopril is a drug designed to lower systolic blood pressure. When subjects were treated with this drug, their systolic blood pressure readings (in mm Hg) were measured before and after the drug was taken. Results are given in the accompanying table. Using a 0.01 significance level, is there sufficient evidence to support the claim that captopril is effective in lowering systolic blood pressure? I J Subject Before After А 200 191 B 174 170 с 198 177 D 170 167 E 179 159 F 182 151 G 193 176 H 209 183 185 159 155 145 K 169 146 A. What type of test is this? i. Left-tailed ii. Right-tailed iii. Two-tailed B. What is the test statistic (to 2 decimal places)? C. What is the critical t-score (to 2 decimal places)? D Which is true about the p-value? i. P-value > 0.10 ii. P-value > 0.01 iii. P-value > 0.001 iv. P-value > 0.0001 v. P-value > 0.00001 vi. None of the above. E. Based on the statistical testing, do you conclude that captopril lowers systolic pressure? vii. Yes viii. No HTML Editora

Answer 1

Note: Final answers are highlighted in colour.

In this question we have two samples in which observations in one sample(Systolic blood pressure Before) can be paired with observations in the other sample(Systolic blood pressure after). These samples are called dependent samples, and we can perform a paired t-test.

Subject	Before	After	Difference di(Before-After)
A	200	191	9
B	174	170	4
C	198	177	21
D	170	167	3
E	179	159	20
F	182	151	31
G	193	176	17
H	209	183	26
I	185	159	26
J	155	145	10
K	169	146	23
		Mean Difference($\overline{d}$)	AVERAGE(D2:D12)= 17.27272727
		Standard Deviation(Sd)	STDEV.S(D2:D12)= 9.466688007

Hypothesis:

H₀:
0 Pr!
(Where
211 Inl Pn
)

H₁:

0 < P71

11
is the mean Systolic blood pressre before captopril drug, $\mu_2$ is the mean Systolic blood pressre after captopril drug.

A) As we are testing the alternate hypothesis of , this is going to be a Right tailed test.

0 < P71

B) Test statistic

t stat=
ul/Ps P
= $\frac{17.273}{9.467/\sqrt{11}}$

= 6.05

C) Critical t - score at 0.01 significance level and degrees of freedom of 10(n-1) is 2.76(From t distribution table)

D) P value for t=6.05, degrees of freedom=10 is 0.000062

P - value > 0.00001 (Option v)

E) As p value(0.000062) < 0.01, we can reject the null hypothesis and conclude that Systolic blood pressure has reduced due to captopril drug.

Based on the statistical testing, Yes we conclude that the captopril drug lowers the blood pressure.