1. The problem statement, all variables and given/known data A random variable has a Poisson distribution with parameter λ = 2. Compute the following probabilities, giving an exact answer and a decimal approximation. P(X ≥ 4) 2. Relevant equations P(X = k) = λke-λ/k! 3. The attempt at a solution P(X ≥ 4) = Ʃk = 4∞ λke-λ/k! = λ4e-λ/4! + λ5e-λ/5! + λ6e-λ/6! + [itex]\cdots[/itex] = e-λ [λ4/4! + λ5/5! + λ6/6! + [itex]\cdots[/itex]] = e-λ Ʃk = 4∞ λk/k! Let n = k - 4 =e-λ Ʃn = 0∞ λn+4/(n+4)! plug in λ = 2 = e-2 Ʃn = 0∞ 2n+4/(n+4)! = e-2 Ʃn = 0∞ 2n24/(n+4)! = 16e-2 Ʃn = 0∞ 2n/(n+4)! This is as far as I have gotten, but I'm not sure I'm on the correct track. I used wolfram alpha to reduce the summation term, Ʃn = 0∞ 2n/(n+4)!, to [1/48(3e2-19)], but I'm at a loss as to how to get there myself. Anyone have any suggestions? It would be greatly appreciated!