4. Four buses carrying 198 students from the same school arrive at a football stadium. The buses carry, respectively 90, 33, 25, and 50 students. One of the students is randomly selected. Let X denote the number of students who were on the bus carrying the randomly selected student. One of the four bus drivers is also randomly selected. Let Y denote the number of students on her bus. 3) Which of E[X] or E[Y] do you think is larger? Why? b) Compute E[X] and EM. c) Find Var(X) and Var(Y)