Exercise 2.25 on page 57 introduces a study of 678 women who had gone off birth control with the intention of becoming pregnant. Table B.6 includes information on whether or not a woman was a smoker and whether or not the woman became pregnant during the first cycle. We wish to estimate the difference in the proportion who successfully get pregnant, between smokers and non smokers.

Table B.6

(a) Find the best point estimate for the difference in proportions.
(b) Use StatKey or other technology to find and interpret a 90% confidence interval for the difference in proportions. Is it plausible that smoking has no effect on pregnancy rate?

Exercise 2.25 on page 57

Studies have concluded that smoking while pregnant can have negative consequences, but could smoking also negatively affect one€™s ability to become pregnant? A study collected data on 678 women who had gone off birth control with the intention of becoming pregnant. Smokers were defined as those who smoked at least one cigarette a day prior to pregnancy. We are interested in the pregnancy rate during the first cycle off birth control. The results are summarized in Table 2.11.

Transcribed Image Text:

Smoker Total Non-smoker Pregnant Not pregnant 38 206 244 97 337 434 Total 543 678 135 Total Smoker 38 Non-smoker Pregnant 206 337 244 434 Not pregnant Total 97 135 543 678