Suppose that bus loads for a certain bus route fluctuate randomly throughout theday. Each bus can be classified as either “packed” or “light”, and there is equal likelihoodthat a given bus is one or the other. Suppose a packed bus carries about 80 students perbus on average. A light bus carries about 20 students on average. To decide whether toincrease the number of busses on that route, Transportation Services decides to use Poissondistributions to model this route.(a) Find the PMF of X = # of students on the next PACKED bus on this route.(b) Find the PMF of Y = # of students on the next LIGHT bus on this route.(c) What is the probability that the next bus will have exactly 35 students init? (Hint: The PMFs you calculated in Parts A and B are conditional PMFs given thenext bus’ type.)
Suppose that bus loads for a certain bus route fluctuate randomly throughout the
day. Each bus can be classified as either “packed” or “light”, and there is equal likelihood
that a given bus is one or the other. Suppose a packed bus carries about 80 students per
bus on average. A light bus carries about 20 students on average. To decide whether to
increase the number of busses on that route, Transportation Services decides to use Poisson
distributions to model this route.
(a) Find the PMF of X = # of students on the next PACKED bus on this route.
(b) Find the PMF of Y = # of students on the next LIGHT bus on this route.
(c) What is the probability that the next bus will have exactly 35 students in
it? (Hint: The PMFs you calculated in Parts A and B are conditional PMFs given the
next bus’ type.)
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