SOC A researcher is studying the effects of the college experience on attitudes, values, and behaviors and is comparing small random samples from each class at the same university. Which of the following differences are significant?

a. Number of “close friends” from another racial or ethnic group

b. Score on a scale that measures political ideology.
On this scale, 10 means “very conservative” and 1 means “very liberal.”

c. Number of minutes spent in the library each day studying