According to the Centers for Disease Control and Prevention, 46.3% of all ninth
ID: 3217042 • Letter: A
Question
According to the Centers for Disease Control and Prevention, 46.3% of all ninth grade students in the United States have tried cigarette smoking. Use the Central Limit Theorem to approximate the probability that in a random sample of 1000 ninth graders, more than 48% of the sample have tried cigarette smoking. In a clinical trial for Chantix (a drug used as an aid to stop smoking. 19 out of 129 people receiving Chantix experienced insomnia, while 13 out of 805 receiving the placebo experienced insomnia. Construct a 95% confidence interval for the difference between the proportion experiencing insomnia between the Chantix groupExplanation / Answer
Here phat=0.463 We will calculate z=phat-p0/SE(p0)
Now SE p0=sqrt(p0*(1-p0)/n)=sqrt(0.463*0.537/1000)=0.016
So P(p>0.48)=P(z>0.48-0.463/0.016)=P(z>1.06)=0.5-P(0<z<1.06)=0.5-0.3554=0.1446