Abstinence? Th e Gallup Youth Survey asked a random sample of 439 U.S. teens aged 13 to 17 whether they thought that young people should wait to have sex until marriage.16 Th e number who said “Yes” was 246.

(a) Do these results give convincing evidence that a majority of U.S. teens would say that young people should wait to have sex until they’re married? Carry out a signifi -

cance test to help answer this question.

(b) Construct and interpret a 95% confi dence interval for the proportion of all teens who would say “Yes” if asked this question.

(c) Do the inference methods in

(a) and

(b) tell us whether the teens who responded to the survey were telling the truth? Explain.