Question

When subjects were treated with a​ drug, their systolic blood pressure readings​ (in mm​ Hg) were measured before and after the drug was taken. Results are given in the table below. Assume that the paired sample data is a simple random sample and that the differences have a distribution that is approximately normal. Using a

0.05

significance​ level, is there sufficient evidence to support the claim that the drug is effective in lowering systolic blood​ pressure?

Before	161	169	158	189	195	165	188	164	155	205	183	159
After	171	186	159	155	176	156	179	148	156	143	144	163

In this example,? ?d? is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the systolic blood pressure reading before the drug was taken minus the reading after the drug was taken. What are the null and alternative hypotheses for the hypothesis test? A. H0: ?d=0 H1: ?d>0 B. H0: ?d?0 H1:?d=0 C. H0: ?d?0 H1:?d>0 D. H0: ?d=0 H1:?d<0 Identify the test statistic. t= _______ (Round to two decimal places as needed.) Identify the P-value. P-value= _______ (Round to three decimal places as needed.) Since the P-value is Less///or////Greater_____??than the significance level, Fail to Reject////or///Reject Ho. There is?Insufficient//or//sufficient____?evidence to support the claim that the drug is effective in lowering systolic blood pressure. ? H0.? There is? ?evidence to support the claim that the drug is effective in lowering systolic blood pressure.

Answer 1

(A)
H0:   

H1:

(B)

From the given data, values of d are got as follows

- 10, - 17, - 1, 34, 19, 9, 9, 16, - 1, 62, 39, -4

From the d values, the following statistics are calculated:

n = 12

= 155/12 = 12.9167

s_d = 22.7734

SE = s_d/

= 22.7734/ = 6.5741

Test statistic is given by:

t = 12.9167/6.5741 = 1.96

So,

t = 1.96

(C)

ndf =n - 1 = 12 - 1 = 11

One Tail - Right Side Test

By Technology, p - value= 0.038

So,

P - Value = 0.038

(D)

Since the P - Value is less than the significance level, Reject H0. There is sufficient evidence to support the claim that the drug is effective in lowering systolic blood pressure.