作者middleroad (勤学统计)
看板Grad-ProbAsk
标题[文商] 统计-96-淡江-保险
时间Sun May 31 14:18:25 2009
Suppose there are two boxes. Box I contains 20 articles, of which 5 are
defective, and box II contains 30 articles, of which 6 are defective.
One article is randomly selected from each box, and the selections from the
two boxes are independent. Let X denote the total mumber of defective articles
obtained. Determine the probability distribution of X.
X→Bin(n=2,p=1/20)
请问 n=2跟p=1/20是怎麽求出来的呢？
谢谢～
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1F：→ a016258:答案不对吧...>.<" 05/31 17:52
2F：→ middleroad:是喔 那麽这题要怎麽算呢 05/31 18:35
3F：推 cutebodlol:就X=0,1,2的状况跟机率都写出来就好 05/31 23:42
4F：→ middleroad:但是我有点看不懂题意 不知道过程怎麽解的 06/01 00:48
5F：推 kerota:P(X=0)=0.75*0.8=0.6 P(X=1)=0.75*0.2+0.25*0.8=0.35 06/01 02:55
6F：→ kerota:P(X=2)=0.25*0.2=0.05 06/01 02:57
7F：推 STREETPOP:K大正解 06/01 12:32