1. Given that the probability that an individual will suffer a certain physical reaction from an injection of a given drug is 0.002, find the probability that, out of 3000 individuals injected,
a) exactly 3,
b) more than 2
will suffer a reaction
ans
a) 0.0892
b) 0.9380
thanks
F.7 poisson distribution~
2011-10-26 6:59 am
回答 (3)
2011-10-26 5:19 pm
✔ 最佳答案
a) λ = 3000 x 0.002 = 6P(exactly 3) = e-6 x 63/3! = 030892
b) P(more than 2) = 1 - e-6(1 + 6/2! + 62/3!) = 0.9752 (pls. verify)
參考: 原創答案
2011-10-27 4:08 am
a) λ = 3000 x 0.002 = 6P(exactly 3) = exp(-6) x 6^3/3! = 0.0892b) P(more than 2) = 1 - exp(-6) - 6exp(-6) - 36exp(-6)/2 = 0.9380
2011-10-27 12:40 am
It is binomial instead.
p=0.002
a. 3000C3 x p^3 * (1-p)^2997
b. 1- 3000C0 x p^0 * (1-p)^3000 - 3000C1 x p^1 * (1-p)^2999 - 3000C2 x p^2 * (1-p)^2998
p=0.002
a. 3000C3 x p^3 * (1-p)^2997
b. 1- 3000C0 x p^0 * (1-p)^3000 - 3000C1 x p^1 * (1-p)^2999 - 3000C2 x p^2 * (1-p)^2998
收錄日期: 2021-04-26 14:55:25
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