The number of accidents that a person has in a given year is a poisson random variable with mean λ. however, we may suppose that the rate λ depends on the person or portion of the population. suppose that λ=4 for 75 percent of the population, and λ=5 for the other 25 percent. (a) if a person is chosen at random, what is the probability that s/he will have zero accidents in a certain year?