The number of typographical errors in a document follows a Poisson distribution with a mean of 4 errors per page. Let $X$ represent the number of errors on 2 pages. Find $P ($ Greater than $1 )$.
A) 0.9970
B) 0.9084
C) 0.9862
D) 0.9997

Question

Quizplus · Accepted Answer

The probability of having more than 1 error on 2 pages is 1 - P(X <= 1). The Poisson distribution with a mean of 4 errors per page has a probability mass function of P(X = k) = (e^-4 * 4^k) / k!. Therefore, P(X <= 1) = P(X = 0) + P(X = 1) = (e^-4 * 4^0) / 0! + (e^-4 * 4^1) / 1! = 0.0183 + 0.0733 = 0.0916. Thus, P(X > 1) = 1 - P(X <= 1) = 1 - 0.0916 = 0.9084.

The Number of Typographical Errors in a Document Follows a Poisson