the cost of a meal might affect how customers evaluate and appreciate food. To investigate, researchers worked with an all Italian all you can eat buffet to perform an experiment. A total of 139 subjects were randomly assigned to pay either 4$. Or 8$ for the buffet and then asked to rate the quality of the pizza on a 9 point scale. Subjects who paid 8$ rated pizza 11% higher than this who paid only $4. Identify the explanatory and response variables, the experimental units, and the treatments.