Question

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. a) Which of E[X] or E[Y] do you think is larger

Answer 1

E[x] is larger

Explanation:

I think E[x] is larger because the expected number of students on the bus of a randomly chosen student is larger.

This is because the higher the number of students present in a bus, the higher the probability that a randomly selected student would have been on that bus.

Whereas, for every driver to be chosen, the probability of any bus being chosen is 1/4 irrespective of the number of students in that particular bus