Chapter 10.6, Problem 73E

The article “Boy or Girl: Which Gender Baby Would You Pick?” (LiveScience, March 23, 2005, livescience.com) summarized the findings of a study that was published in Fertility and Sterility. The LiveScience article makes the following statements: “When given the opportunity to choose the sex of their baby, women are just as likely to choose pink socks as blue, a new study shows” and “Of the 561 women who participated in the study, 229 said they would like to choose the sex of a future child. Among these 229, there was no greater demand for boys or girls.” These statements are equivalent to the claim that for women who would like to choose the baby’s sex, the proportion who would choose a girl is 0.50 or 50%.

1. a. The journal article on which the LiveScience summary was based (“Preimplantation Sex-Selection Demand and Preferences in an Infertility Population,” Fertility and Sterility [2005]: 649–658) states that of the 229 women who wanted to select the baby’s sex, 89 wanted a boy and 140 wanted a girl. Does this provide convincing evidence against the statement of no preference in the LiveScience summary? Test the relevant hypotheses using α = 0.05. Be sure to state any assumptions you must make about the way the sample was selected in order for your test to be appropriate.
2. b. The journal article also provided the following information about the study:
   • A survey with 19 questions was mailed to 1385 women who had visited the Center for Reproductive Medicine at Brigham and Women’s Hospital.
   • women returned the survey.

Do you think it is reasonable to generalize the results from this survey to a larger population?

Do you have any concerns about the way the sample was selected or about potential sources of bias? Explain.