A university lecturer receives,on average,24.7 e-mails from students the day before the final exam.To compute the probability of receiving at least 10 e-mails on such a day,he will use what type of probability distribution?
A) Binomial distribution.
B) Poisson distribution.
C) Hypergeometric distribution.
D) None of the above.

Question

Quizplus · Accepted Answer

The situation described fits the Poisson distribution, which models the number of times an event happens in a fixed interval of time or space, given the expected average rate of occurrences and assuming that events happen independently and randomly. The Poisson distribution is often used in situations involving rare events, where the probability of occurrence of a single event is small, but the number of opportunities for the event to happen is large (as in the case of receiving e-mails from students). The binomial distribution models the number of successes in a fixed number of independent trials with two possible outcomes, and the hypergeometric distribution models the number of successes in a sample drawn from a finite population of two types of items, each with a known size and frequency. Neither of these distributions applies to the situation described.

A University Lecturer Receives,on Average,24