求救！一個有關概率的問題！
2007-10-15 8:58 am
A bag of candy has a statement on it that reads "Approximately 20 pieces (Poisson distribution)". What is the probability that you purchased a bag with only 18 pieces? What is the probability with 18 or less pieces?
回答 (2)
2007-10-15 9:24 am
參考: My Maths knowledge
2007-10-15 9:21 am
Poisson distribution: a^k e^(-a)/k!, where a is the mean and k is occurrence.
So, P(18) = 20^18 e^(-20)/ 18!
P(=<18) = Gamma(19,20)/18!
where Gamma is the Incomplete Gamma function.
Read: http://en.wikipedia.org/wiki/Poisson_distribution
So, P(18) = 20^18 e^(-20)/ 18!
P(=<18) = Gamma(19,20)/18!
where Gamma is the Incomplete Gamma function.
Read: http://en.wikipedia.org/wiki/Poisson_distribution
收錄日期: 2021-04-23 20:07:05
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20071015000051KK00200