In studying the product life cycle in the commercial mainframe computer market over the period 1968 to 1982, Shane Greenstein (Northwestern University) and James Wade (University of Illinois) found that the number of new product introductions per year per firm, 1 E x, could be approximated by a Poisson random variable with mean equal to .37 (Rand Journal of Economics, Winter 1998).

a. Find the standard deviation of x.

b. Plot p(x), the probability distribution for x.

c. Is it likely that the mainframe manufacturer would introduce more than two new products per year? I Less than one new product per year? Justify your j answers.