Question

A pharmaceutical company claims that its new drug reduces systolic blood pressure. The systolic blood pressure (in millimeters of mercury) for nine patients before taking the new drug and 22 hours after taking the drug are shown in the table below. Is there enough evidence to support the company's claim?

Let d=(blood pressure before taking new drug)−(blood pressure after taking new drug)d=(blood pressure before taking new drug)−(blood pressure after taking new drug). Use a significance level of α=0.1 for the test. Assume that the systolic blood pressure levels are normally distributed for the population of patients both before and after taking the new drug.

Patient	1	2	3	4	5	6	7	8	9
Blood pressure (before)	204	204	167	200	176	171	202	193	173
Blood pressure (after)	183	194	148	187	163	164	189	184	153

Step 1 of 5: State the null and alternative hypotheses for the test.

Step 2 of 5: Find the value of the standard deviation of the paired differences. Round your answer to one decimal place.

Step 3 of 5: Compute the value of the test statistic. Round your answer to three decimal places.

Step 4 of 5: Determine the decision rule for rejecting the null hypothesis H0H0. Round the numerical portion of your answer to three decimal places.

...reject H0 if

Step 5 of 5: Make the decision for the hypothesis test.

...Reject Null Hypothesis....Fail to Reject Null Hypothesis

Answer 1

Ans:

	before	after	d
1	204	183	21
2	204	194	10
3	167	148	19
4	200	187	13
5	176	163	13
6	171	164	7
7	202	189	13
8	193	184	9
9	173	153	20
		d-bar	13.889
		sd	5.036

1)

2)

	before	after	d
1	204	183	21
2	204	194	10
3	167	148	19
4	200	187	13
5	176	163	13
6	171	164	7
7	202	189	13
8	193	184	9
9	173	153	20
		d-bar	13.889
		sd	5.036

standard deviation of the paired differences,sd=5.0

3)

Test statistic:

t=(13.889-0)/(5.036/sqrt(9))

t=8.274

(if sd=5.0 has to be considered,then t=8.333)

4)df=9-1=8

critical t value=1.397

Reject H₀,if t>1.397

5)

.Reject Null Hypothesis