Find the indicated probabilities using the geometric distribution, the Poisson distribution, or the binomial distribution. Then determine if the events are unusual. If convenient, use the appropriate probability table or technology to find the probabilities. A newspaper finds that the mean number of typographical errors per page is five. Find the probability that (a) exactly four typographical errors are found on a page, (b) at most four typographical errors are found on a page, and (c) more than four typographical errors are found on a page.

(a) P(exactly four typographical errors are found on a page) = (Round to four decimal places as needed.)

(b) P(at most four typographical errors are found on a page) =

(c) P(more than four typographical errors are found on a page) =

Which one if any is unusual and why?