Let X be the number of students who show up for a professor's office hour on a particular day. Suppose that the pmf of X is p(0) = .20, p(1) = .25, p(2) = .30, p(3) = .15, and p(4) = .10.
a. Draw the corresponding probability histogram.
b. What is the probability that at least two students show up? More than two students show up?
c. What is the probability that between one and three students, inclusive, show up?
d. What is the probability that the professor shows up?