Ecologists often use the number of reported sightings of a rare species of animal to

estimate the remaining population size. For example, suppose the number, X, of

reported sightings per week of blue whales is recorded. Assume that X has

approximately Poisson distribution. Furthermore, assume that the average number of

weekly sightings is 3.

a) Find the mean and standard deviation of X, the number of blue whale sightings

per week.

b) Find the probability that fewer than two sightings are made during a given

week.

c) Find the probability that more than five sightings are made during 2 week

period.