Application and computer review of some probability models

The Poisson random variable has a tremendous range of application in diverse areas, because it may be used as an approximation for a binomial random variable with parameters (n,p). In practice, the exponential distribution often arises as the distribution of the amount of time until some form now until an earthquake occurs, or until a telephone call you receive turns out to be a wrong number at all random variables that tend in practice to have exponential distribution.