A professor has been asked to teach a course in social science statistics off-campus to a class of graduate students enrolled in the Continuing Education Program of the University. Because the professor has never taught in this program before, he does not know a great deal about the needs and backgrounds of the students in the class. In order to learn more about the students, on the first day of class he obtains from each of them the following information: age, major field as an undergraduate student, number of statistics courses taken previously, and interest in conducting empirical research (coded low, medium, high). This information is listed below:

(a) At what level of measurement is each of these variables?
(b) In order to summarize this data, the professor decides to calculate measures of central tendency for these variables. For each variable, which measures of the central tendency can meaningfully be calculated?

Student # Age Major Poli Sci Zoology Botany Sociology Poli Sci Sociology Poli Sci Forestry Engineering Poli Sci Chemistry Sociology Physics Sociology Poli Sci Poli Sci Sociology Statistics Courses Research Interest 24 High 26 ow oW Low Medium Medium Low High Medium Medium 56 53 26 24 54 51 10 12 ow 13 High High 15 oW 16 25 Medium Medium