Abcott Institute Distribution of Sample Proportions Discussion


The National Health Survey uses household interviews to describe
the health-related habits of U.S. adults. From these interviews they estimate
population parameters associated with behaviors such as alcohol consumption,
cigarette smoking, and hours of sleep for all U.S. adults.

In the 2005-2007 report, they estimated that 30% of all current
smokers started smoking before the age of 16. Imagine that we want to verify
this estimate. So we randomly select a sample of 100 smokers and calculate the
proportion who started smoking before the age of 16. How much error do we
expect in the sample proportions if the 30% is correct for the population
overall? Use the applet and a give an error based on 2 standard deviations.