A local radio station conducted a survey about stay-at-home parents by randomly dialing home numbers on weekdays until responses from 500 adults were collected. Twenty-six percent of those who responded said they were stay-at-home parents. In reality, only four percent were actually stay-at-home parents at the time of the survey. Which of the following best explains the difference in the two percentages? a. The difference is due to voluntary response. Adults are able to volunteer as members of the sample.
b. The difference is due to undercoverage bias. The survey included only adults with telephones.
c. The difference is due to response bias. Adults who are stay-at-home parents are likely to say they are employed outside the home.
d. The difference is due to sampling variability. We should not expect the results of a random sample to match the truth about the population every time.
e. The difference is due to nonresponse bias. Adults who are stay-at-home parents are more likely to be available for the sample than adults who are employed outside the home.