2.1.1044 Part 4 Section 3.17.7.251, POISSON

a.   The standard stated that if argument mean ≤ 0, #NUM! is returned.

Office returns #NUM! if argument mean is < 0.

b.   The standard states the formula for CUMPOISSON =  ∑_(k=0)^x((e^(-λ) λ^x)/k!).

Office requires CUMPOISSON = ∑_(k=0)^x((e^(-λ) λ^k)/k!).

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