Nicole is back at it again and wants to see, this time, if listening to classical music while taking a test affects test scores. She is going to design an experiment to answer the question: Does listening to classical music while taking a test improve test scores? She will conduct this experiment with the 20 students in her class. (a) What are the experimental units?
explanatory variable?
treatments?
response variable?

(b) What other potential variable could confound the results in this situation? How could they affect the results? How could we avoid their effects?

(c) Describe and design a completely randomized design for Nicole's experiment