Confidence Intervals for Population Proportion: Videos & Practice Problems

$95\%$ CI for biochemical confirmation:

$95\%$ CI for self-reported quitting:

The $95\%$ CIs for both self-reported quitting and biochemical confirmation are equal in width. Therefore, quitting rates for both confirmation methods are the same.

$95\%$ CI for biochemical confirmation:

$95\%$ CI for self-reported quitting:

The $95\%$ CI for self-reported quitting is narrower than the $95\%$ CI for biochemical confirmation. Therefore, the biochemical test indicates a lower quitting rate than self-reporting.

$95\%$ CI for biochemical confirmation:

$95\%$ CI for self-reported quitting:

The $95\%$ CI for self-reported quitting is wider than the $95\%$ CI for biochemical confirmation. Therefore, people are more likely to claim they have quit smoking than to be confirmed by a biochemical test.

$95\%$ CI for biochemical confirmation:

$95\%$ CI for self-reported quitting:

The $95\%$ CIs for both self-reported quitting and biochemical confirmation overlap. Therefore, the results are inconclusive because the sample sizes are too small to draw any meaningful conclusions.