Identify all variables in the research situations listed below and classify them by their level of measurement. Which variables are independent and which are dependent?

a. A researcher is wondering about racial preferences in dating among college students and asks a large sample of undergraduates about their own racial self-identification. She then asks the respondents to rank some racial-ethnic categories (stated as white, black, Latino, Asian) in terms of desirability as potential dates.

b. For high school students, does GPA affect sexual activity? A sample has been interviewed about the number of different romantic relationships they have had, the number of times they have had sexual intercourse, and their high school grade-point average.

c. Several hundred voting precincts across the nation have been classified in terms of percentage of minority voters, voting turnout, and percentage of local elected officials who are members of minority groups. Do precincts with higher percentages of minority voters have lower turnout? Do precincts with higher percentages of minority elected officials have higher turnout?

d. As nations become more affluent (as measured by per capita income), does the percentage of children enrolled in school increase? Is this relationship different for boys and girls?

e. Does the level of support for gun control vary by number of years of schooling? Does this relationship vary by gender, region of the country, or political party preference? Support for gun control was measured by a five-point scale that ranged from “strongly in favor” to “strongly opposed.”