Refer to News Story 2 in the Appendix and
on the CD, “Research shows women harder hit by hangovers,” and the accompanying
Original Source 2 on the CD, “Development and initial validation of the
Hangover Symptoms Scale: Prevalence and correlates of hangover symptoms in
college students.” Table 3 of the journal article reports that 13% of the 1216
college students in the study said that they had not experienced any hangover
symptoms in the past year.
a. Assuming that the participants in this
study are a representative sample of college students, find a 95% confidence
interval for the proportion of college students who have not experienced any
hangover symptoms in the past year. Use the formula in this chapter.
b. Write a sentence or two interpreting the
interval you found in part a that would be understood by someone without
training in statistics.
c. The journal article also reported that
the study originally had 1474 participants, but only 1234 reported drinking any
alcohol in the past year. (Only those who reported drinking in the past year
were retained for the hangover symptom questions.) Use this information to find
a 95% confidence interval for the proportion of all students who would report
drinking any alcohol in the past year.
d. Refer to the journal article to
determine how students were selected for this study. Based on that information,
to what population of students do you think the intervals in this exercise
apply? Explain.