> > > > Problem 7BSC

use the Wilcoxon rank-sum test. Clinical Trials of Lipitor

Problem 7BSC Chapter 13.4

Elementary Statistics | 12th Edition

• 2901 Step-by-step solutions solved by professors and subject experts
• Get 24/7 help from StudySoup virtual teaching assistants

Elementary Statistics | 12th Edition

4 5 0 386 Reviews
17
0
Problem 7BSC

use the Wilcoxon rank-sum test. Clinical Trials of Lipitor ?The sample data below are changes in LDL cholesterol levels in clinical trials of Lipitor (atorvastatin). It was claimed that Lipitor had an effect on LDL cholesterol. (The data are based on results given in a Parke-Davis memo from David G. Orloff, M.D., the medical team leader for clinical trials of Lipitor. Pfizer declined to provide die author with the original data values.) Negative values represent decreases in LDL cholesterol. Use a 0.05 significance level to test the claim that for those treated with 20 mg of atorvastatin and those treated widi 80 mg of atorvastatin, changes in LDL cholesterol have the same median. What do the results suggest? Group treated with 20 mg of atorvastatin: ?28 ?32 ?29 ?39 ?31 ?35 ?25 ?36 ?35 ?26 ?29 ?34 ?30 Group treated with 80 mg of atorvastatin: ?42 ?41 ?38 ?42 ?41 ?41 ?40 ?44 ?32 ?37 ?41 ?37 ?34 ?31

Step-by-Step Solution:

Solution 7BSC Step 1 : Given, The given data is changes in LDL cholesterol levels taken randomly, so the observations from the same population. Hence first requirement of the Wilcoxon Rank-Sum test satisfied. Each samples contains 13 values of the changes in LDL cholesterol level of group treated with 20 mg of Atorvastatin and 14 values of the changes in LDL cholesterol level of group treated with 20 mg of Atorvastatin , it satisfies the second condition that the each sample should have the same median. Therefore, both the requirements of the Wilcoxon Sum-Rank test satisfies. Hypothesis : H : The median of changes in LDL cholesterol level of group treated with 20 mg of 0 Atorvastatin is equal to the changes in LDL cholesterol level of group treated with 80 mg of Atorvastatin H 1 The median of changes in LDL cholesterol level of group treated with 20 mg of Atorvastatin is not equal to the changes in LDL cholesterol level of group treated with 80 mg of Atorvastatin Step 2 : We have 27 observations, based on the values we give ranks, if it is least value then rank will be 1 and next to the value will be 2 and so on. If there is a tie then mean of the values is the rank, Highest value is 44 which is assigned the rank 27. Ranks for LDL cholesterol levels of the group treated with 20 mg of Atorvastatin are 4, 10.5, 5.5, 20, 8.5, 14.5, 2, 16, 14.5, 3, 5.5, 12.5, 7. The sum of the ranks for LDL cholesterol levels of the group treated with 20 mg of Atorvastatin = 123.5

Step 3 of 4

Step 4 of 4

Related chapters

×
Log in to StudySoup
Get Full Access to Elementary Statistics - 12th Edition - Chapter 13.4 - Problem 7bsc

Forgot password? Reset password here

Join StudySoup for FREE
Get Full Access to Elementary Statistics - 12th Edition - Chapter 13.4 - Problem 7bsc
Already have an account? Login here
Reset your password

I don't want to reset my password

Need help? Contact support

Need an Account? Is not associated with an account
We're here to help

Having trouble accessing your account? Let us help you, contact support at +1(510) 944-1054 or support@studysoup.com

Password Reset Request Sent An email has been sent to the email address associated to your account. Follow the link in the email to reset your password. If you're having trouble finding our email please check your spam folder
Already have an Account? Is already in use
Incorrect Password The password used to log in with this account is incorrect

Forgot password? Reset it here