84 Suppose x is a random variable for which a Poisson probability distribution with l = 1 provides a good characterization.

a. Graph p1x2 for x = 0, 1 , 2 ,

c, 9 .

b. Find m and s for x , and locate m and the interval m { 2s on the graph.

c. What is the probability that x will fall within the interval m { 2s ?