In a clinical trial of a drug used to help people stop smoking, 821 people were
ID: 3360571 • Letter: I
Question
In a clinical trial of a drug used to help people stop smoking, 821 people were treated with 1 mg of chantrix. The group consisted of 30 people who experienced nausea(based on data from Pfizer, Inc.)
a. construct a 99% confidence interval estimate of the proportion of people treated with 1mg of chantrix who experienced nausea.
b. assuming that the probability of nausea for subjects not receiving the treatment was 0.0124, (chantix has no effect), is it unusual to find that there are 30 who experienced nausea among
Explanation / Answer
A) P = 30/821 = 0.0365
At 99% confidence interval the critical value is Z0.995 = 2.58
The confidence interval is
P +/- Z0.995 * sqrt (P * (1 - P)/n)
= 0.04 +/- 2.58 * sqrt (0.0365 * 0.9635 / 821)
= 0.04 +/- 2.58 * 0.0065
= 0.04 +/- 0.0168
= 0.0232, 0.0568
B) as 0.0124 < 0.05, so it is unusual.