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If x~Po(6)then find $$P(x=6|5≤ x ≤ 8 )$$ I understand that this is conditional probability but I do not understand how would you solve it?

  • 0
    Must $x$ take on integer values only? Is your distribution function uniform?2017-02-23
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    its a poisson distribution2017-02-23
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    OK, I was wondering what the $x\sim Po(6)$ meant.2017-02-23

1 Answers 1

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\begin{align}P(X=6|5 \leq X \leq 8)&=\frac{P(X=6)}{P(5 \leq X \leq 8)}\\&=\frac{P(X=6)}{\sum_{i=5}^8P(X=i)} \\&=\frac{\exp(-\lambda)\frac{\lambda^6}{6!}}{\sum_{i=5}^8\exp(-\lambda)\frac{\lambda^i}{i!}} \\&=\frac{\frac{\lambda^6}{6!}}{\sum_{i=5}^8\frac{\lambda^i}{i!}}\end{align}

where $\lambda = 6$.