2. Four buses carrying 180 students from the same school. Bus A carries 60 students; Bus B carries 37 students; Bus C carries 30 students and Bus D carries 53 students. We first randomly select a student. Let X be the random variable representing the number of students that were on the bus carrying the randomly selected student. We do another trial that one of the 4 bus drivers is randomly selected. Let Y be the random variable denoting the number of students on his/her bus. Which expectation value will be larger? E[X] or the E[Y]? Prove your statement numerically.