Refer to News Story 2 in the Appendix and on the book’s website, “Research shows women harder hit by hangovers,” and the accompanying Original Source 2 on the website, “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.