The document discusses probabilities related to the number of drivers traveling between an origin and destination within a time period, where the number of drivers has a Poisson distribution with a parameter of 20. It asks for the probability that the number of drivers will be: (1) at most 11; (2) greater than 26; (3) between 11 and 26 inclusive or strictly between 11 and 26; and (4) within 2 standard deviations of the mean value.

1. Suppose that the number of drivers who travel between a particular origin and destination during a
designated time period has a Poisson distribution with parameter =20 (suggested in the article
"Dynamic Ride Sharing: Theory and Practice" t ). (Round your answer to three decimal places.) (a)
What is the probability that the number of drivers will be at most 11? (b) What is the probability
that the number of drivers will exceed 26 ? (c) What is the probability that the number of drivers
will be between 11 and 26, inclusive? What is the probability that the number of drivers will be
strictly between 11 and 26? (d) What is the probability that the number of drivers will be within 2
standard deviations of the mean yalue?