Question z (4 pts]. A college professor writes two final exams for her class of 60 and would like to know if the two exams are similar in difficulty. On exam day, she gives Exam A to the first 30 students to enter the classroom and Exam B to the remaining 30 students. (a) What is the explanatory variable? What is the response variable? (2pts) (b) Is this a randomized experiment? What might be a confounding variable? (2pts)