Arrival of vehicles at New Jersey Turnpike toll booth on Saturdays at dawn is modeled as a Poisson Arrival process with a rate of 1.21 vehicles per minute. Let X be a random variable that records the number of arrivals between 4:45AM and 5:15AM.
(a) Is this variable finite discrete, infinite discrete, or continuous?
(b) What is the distribution of X and the expected value of X?