The curator of a fossil museum finds there were 1450 visitors in May and 1890 visitors in June. At the beginning of June, he had hired Bert McGruff, a popular local athlete, to serve as a tour guide. Mr. McGruff, pointing out the increase in attendance, has demanded a raise in pay. Considering this situation as an experiment:
a. Identify the dependent and independent variables in this experiment.
b. Are there any extraneous variables that might have influenced this experiment?
c. Given your response to part (b), evaluate the internal validity of the experiment. Does Bert's request for a raise seem to be justified?