In a clinical trial of Lipitor, a common drug used to lower cholesterol, 863 pat
ID: 3219098 • Letter: I
Question
In a clinical trial of Lipitor, a common drug used to lower cholesterol, 863 patients were given a treatment of 10mg Atorvastatin tablets. That group contains 19 patients who experienced flu symptoms (based on data from Pfizer, Inc.). The probability of fly symptoms for a person not receiving any treatment is 0.019.
A- Assuming that Lipitor has no effect on flu symptoms, find the mean and standard deviation for the numbers of people in groups of 863 that can be expected to have flu symptoms.
B- Based on the result from part (a), is it unusual to find that among 863 people, there are 19 who experience flu symptoms? Why or why not?
C- Based on the preceding results, do flu symptoms appear to be an adverse reaction that should be of concern to those who use Lipitor?
Explanation / Answer
a)here mean =np=863*0.019=16.397
std deviation=(np(1-p))1/2 =4.01
B) for we know that z=(X-mean)/std deviation
hence P(X>=19)=1-P(X<=18)=1-P(Z<(18.5-16.397)/4.01)=1-P(Z<0.602)=1-0.7264 =0.2736
as above probabilty is higher then 0.05 level we can not consider that to be unusual
c) we can not say that for sure as above probability is not considered to be unusual