Unformatted text preview: P ( X ≤ 8 ) = P( X < 8.5 ) T P ( X < 8.5 ) = < 19 . 2 6 5 . 8 Z P = P ( Z < 1.14 ) = 0.8729 . ( Binomial distribution, n = 30, p = 0.20, P ( X ≤ 8 ) = 0.87135. ) 2. (5) A communication system for a company has 40 outside lines. If the number X of line requests at a given time follows a Poisson distribution with mean 36, compute the probability that an incoming call cannot find an open line. That is, find the probability that the number of lines needed, X, exceeds 40. (Use Normal approximation.) Need P(X > 40) = ? o μ = λ = 36. σ = λ = 6. t 0.5 correction: do not want 40, want 41. P(X > 40.5) = ? T P(X > 40.5) = P < 6 36 5 . 40 Z = P(Z > 0.75) = 1 – Φ (0.75) = 0.2266 . ( Poisson distribution, λ = 36, P(X > 40) = 0.2229. )...
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This note was uploaded on 11/28/2011 for the course STAT 400 taught by Professor Kim during the Spring '08 term at University of Illinois, Urbana Champaign.
 Spring '08
 Kim

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