The January 17, 1994 issue of Time magazine reported that 58% of adult Americans said yes to the question “If you or your spouse were pregnant, would you want the unborn child tested for genetic defects?” These results were based on a telephone poll of 500 adult Americans. Let p equal the proportion of adult Americans who would say yes to this question.
(a) Give the endpoints for a 90% confidence intervalfor p.
(b) The poll takers claimed that their samplingerror was 4.5%. What is their confidence coefficient?
The solution discusses a confidence interval and confidence coefficient for proportion.