Suppose that our editor makes an average of two and one-half typographical errors per page. You select a 30-page chapter on this text at random and let C denote the total number of typos in the chapter.
(a) Find $\mu_C$
Alright this looks like a really simple question, but I'm so confused. It says in my text:
Mean and Variance of a Poisson Random Variable
Suppose that Z is a Poisson random variable with parameter $\lambda$. Then
So $\mu_C$ is just the expected value and at first I thought the solution is just 2.5, but its really $2.5*30=75$. Can someone please explain what I am misunderstanding with lambda and the theorem in my book? Thank you in advance.