Consider data from the American Journal of Cardiology (1985) on the relationship between
biological sex of the individual, smoking, and aortic stenosis (a heart condition). The data are as
shown in the table below.
Sex (X) Smoker Status (Y) Aortic Stenosis No Aortic Stenosis
Female
Non-smoker
29
47
Smoker
14
19
Male
Non-smoker
25
20
Smoker
37
24
A1. What is the most conservative minimum sample size required to produce a 99% confidence
interval with an approximate margin of error of 0.04 for the probability of a female non-smoker
having aortic stenosis?
(3 Marks)
a. $n = 106$
b. $n = 601$
c. $n = 979$
d. $n = 1,037$
Answer:
A2. Using the table above and focusing strictly on female non-smokers, produce a standard
Wald 95% confidence interval for the probability of a female non-smoker having aortic stenosis
(to 3dp).
(3 Marks)
a. (0.252, 0.511)
b. (0.272, 0.491)
c. (0.281, 0.494)
d. (0.290, 0.473)
Answer: