Which Nonparametric Test Should Be Used to Analyze of Data

Short Answer

Which nonparametric test should be used to analyze of data from the following studies?
a. An experimenter wanted a measure of the relationship between the ranks of students in their high school graduating class and their ranks in their college graduating class.
b. Three groups of registered voters (rural residents, urban residents, and suburban residents) completed a questionnaire measuring their attitudes toward the Congress.
c. Fifteen male and 15 female assistant professors were ranked according to their salaries to determine whether sex discrimination existed at the university.