Question: A typesetting agency used by a scientific journal employs two typesetters. Let X1 and X2 denote the number of errors committed by typesetter 1 and 2, respectively, when asked to typeset an article. Suppose that X1 and X2 are Poisson random variables with expected values 2.6 and 3.8, respectively.
(a) What is the variance of X1 and of X2?
(b) Suppose that typesetter 1 handles 60% of the articles. Find the probability that the next article will have no errors.
(c) If an article has no typesetting errors, what is the probability it was typeset by the second typesetter?