A survey was taken of students at a large university in the fall of 2003 who were enrolled in one of three introductory statistics courses: Stat 200, commonly taken by students in the social sciences; Stat 1000, taken by students in the natural sciences; and Stat 1100, taken by business majors. Among other things, students were asked if they had pierced ears.
a. Use software to access the student survey data. Report the percentage with pierced ears for students in the social scienceoriented course, students in the natural science-oriented course, and students in the business-oriented course.
b. The percentage with pierced ears is substantially higher among social science students, and substantially lower among business students. What is a possible confounding variable that is the real reason for a relationship between course taken and having pierced ears or not?
c. To determine the true nature of the relationship between course taken and having ears pierced or not, what would be the next step to take: Construct separate tables for each of the values of the possible confounding variable, or take larger samples in all groups?