US. airlines fly approximately 48 billion passenger-miles per month and average about 2.63 fatalities per month

(Statistical Abstract of the United States: 1998). Assume the probability distribution for x, the number of fatalities per month, can bc approximated by a Poisson probability distribution.

a. What is the probability that no fatalities will occur during any given month? [Hint: Either use Table I11 of Appendix B and interpolate to approximate the probability, or use a calculator or computer to calculate the probability exactly.]

b. Find E(x) and the standard deviation of x.

c. Use your answers to part b to describe the probability that as many as 10 fatalities will occur in any given month.

d. Discuss conditions that would make the Poisson assumption plausible.