Which Nonparametric Test Should Be Used to Analyze of the Data

Short Answer

Which nonparametric test should be used to analyze of the data from the following studies?
a. Julia and Davi were interested in the effects of music on reading comprehension in 5th graders. They played pop-rock, easy listening, or no music to different groups while they were reading. Later the students took a test over the material they read.
b. Kelly and Aubrey gave students a test of Machiavellianism (manipulativeness of others) and divided them into high and low scorers. Students then learned a motor skills test. High math scorers were compared to low scorers.
c. Carla compared the attitudes of African-American and Caucasian students on the Cultural Attitudes Inventory.