a clinical trial is conducted to compare an experimental medication to placebo t
ID: 3431989 • Letter: A
Question
a clinical trial is conducted to compare an experimental medication to placebo to reduce the symptoms of asthma. 200 participants are enrolled in the study and randomized to receive either the experimental medication or placebo
characteristic: experimental medication (n=100) placebo (n=100)
mean (SD) age, year: experimental medication 47.2 (SD=4.3) placebo 46.1 (SD=5.1)
generate a 95% confidence interval for the mean age among participants assigned to the placebo.
a.) (46.35, 48.04)
b.) (45.1, 47.1)
c.) (-46.1, +46.1)
Explanation / Answer
standard error(s.e)= s.d/sqrt(n)=5.1/10=0.51
CI=(mean - 1.96*s.e,mean + 1.96*s.e)
=(46.1 -1.96*0.51,46.1+0.98)
=(45.1,47.1)