geometric distribution

Question

A newspaper find that the mean number of typographical error's per page is six find the probability that at most five topographical errors are found on page

Answer 1

As the other answers have stated, this appears to be a Poisson distribution problem.

 

For a Poisson distribution, the probability of an event is

 

P(k) = λ^k e^-λ /k!

 

where λ is the distribution mean (6 for this problem)

k is an integer number of times an event occurs in an interval

 (the interval for this problem is a page)

 

The probability asked for is P(0) + P(1) + P(2) + P(3) + P(4) + P(5)

  This is the probability of at most 5 events (typos) in the interval (page)

 

Plugging in one gets

 e^-6 (1 + 6 + 18 + 36 + 54 + 64.8)

This works out to be ~ 0.446