A clinical trial is planned to compare an experimental medication designed to lo
ID: 3154077 • Letter: A
Question
A clinical trial is planned to compare an experimental medication designed to lower blood pressure to a placebo. Suppose that patients were recruited from 3 different clinical sites. Use the following data to test if hypertension and clinical site are independent. Run the test at a 5% level of significance. 1) Write out the appropriate null hypothesis and alternative hypothesis; 2) Calculate the test statistic; 3) Give your conclusion including a comparison to alpha or the critical value.
Site 1
Site 2
Site 3
Hypertensive
10
14
12
Not Hypertensive
68
56
40
Site 1
Site 2
Site 3
Hypertensive
10
14
12
Not Hypertensive
68
56
40
Explanation / Answer
1.
Ho: Hypertension and clinical site are independent.
Ha: Hypertension and clinical site are not independent.
**************************
2.
Doing an Expected Value Chart,
14.04 12.6 9.36
63.96 57.4 42.64
Using chi^2 = Sum[(O - E)^2/E],
chi^2 = 2.515461052 [ANSWER, TEST STATISITC]
************************
3.
With df = (a - 1)(b - 1), where a and b are the number of categories of each variable,
a = 3
b = 2
df = 2
Thus, the critical value is
significance level = 0.05
chi^2(critical) = 5.991464547
Also, the p value is
P = 0.284298503
As chi^2 < 5.991, and P > 0.05, we FAIL TO REJECT THE NULL HYPOTHESIS.
Thus, there is no significant evidence that hypertension and clinical site are not independent at 0.05 level. [CONCLUSION]
Related Questions
drjack9650@gmail.com
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.