Problem 19BSC
Clinical Trial of Lipitor Lipitor is the trade name of the drug atorvastatin, which is used to reduce cholesterol in patients. (Until its patent expired in 2011, this was the largestselling drug in the world, with annual sales of $13 billion.) Adverse reactions have been studied in clinical trials, and the table below summarizes results for infections in patients from different treatment groups (based on data from ParkeDavis). Use a 0.01 significance level to test the claim that getting an infection is independent of the treatment. Does the atorvastatin treatment appear to have an effect on infections?

Placebo 
Atorvastatin 10 mg 
Atorvastatin 40 mg 
Atorvastatin 80 mg 
Infection 
27 
89 
8 
7 
No Infection 
243 
774 
71 
87 
Solution 19BSC
Step 1 of 1</p>
We are given a data set of infections among people given different groups of treatments. We have to test the claim that getting an infection is independent of the treatment.
Step 1: To test the claim we need to fulfil certain assumptions.
1. We assume that the sample has been randomly selected because of the structure of the study.
2. The results are tabulated as frequencies.
3. The expected frequencies are more than five in every column.
Step 2 : We will define hypothesis as below
= Getting an infection is an independent of the treatment.
= Getting an infection is not an independent of the treatment.