3. Airlines often oversell tickets. Suppose that 104 passengers have tickets for a plane with only 100 seats. Let X be the number of ticketed passengers who show up for the ight. Assume that the probability mass function of X is given by a: 96 97 98 99 100 101 102 103 104 39(13) .15 .12 .14 .25 .17 .06 .05 .04 .02' (a) Use R to plot the pmf of X. (b) What are the probabilities of P(X 5 100) and P(98 100, 4 x $200 o/W. What are the expected prot E[Z] and the standard deviation S.D.(Z)