A large multinational banking company wants to determine whether there is a significant difference in the average dollar amounts purchased by users of different types of credit cards. Among the credit cards being studied are MasterCard, Visa, Discover, and American Express.
a. If an experimental design were set up for such a study, what are some possible independent variables?
b. List at least three levels, or classifications, for each independent variable.
c. What are some possible dependent variables for this experiment?