※ 引述《brettchen (藍色草原)》之銘言：
: Because not all airline passengers show up for their
: reserved seat, an airline sells 125 tickets for a flight
: that holds only 120 passengers. the probability that
: a passenger does not show up is 0.10, and the passengers
: behave independently.
: (a) What is the probability that every
: passengers who shows up gets a seat?
: 課本的解答是 0.9961
^^^^^^ 0.9916 ?
: 不過跟我答案有出入，我想是英文翻譯問題，看起來怪怪的
: 懇請指教
令X代表有去搭車的乘客
. 2
X~Bin(n=125,p=1-0.1=0.9)~N(μ=125*0.9=112.5,σ =125*0.9*0.1=11.25)
P(X≦120)=P(X<120.5)≒P(Z< (120.5-112.5)/√11.25 )=P(Z<2.39)=0.9916
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