[計量] CAT test7

看板GRE (GRE入學考試)作者 (USC)時間16年前 (2009/12/11 10:01), 編輯推噓3(302)
留言5則, 3人參與, 最新討論串4/4 (看更多)
1.an experiment has 3 outcomes,I,J,K the probabilities of the outcomes are 0.25 0.35 and 0.40,respectively. if it would be performed twice and the successive outcomes are independent, what is the probability that K will not be an outcome either time? ~~~~~ ----------------- 答案是0.36 我的疑問是...難道是直接0.6^2嗎? 不用算另外兩次的機率嗎? 也就是(0.25*0.35*0.6)^2? -------- 謝謝^^ -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 140.138.31.203

12/11 10:04, , 1F
(1-0.4)^2 (一減去發生的機率)^兩次
12/11 10:04, 1F

12/11 10:06, , 2F
independent=>除了K之外可以看成另一件事發生:0.6
12/11 10:06, 2F

12/11 10:41, , 3F
是以不會出現K的機率為(0.35+0.25),發生兩次又獨立
12/11 10:41, 3F

12/11 10:42, , 4F
所以是0.6*0.6
12/11 10:42, 4F

12/15 09:38, , 5F
遇到這種古典機率用列舉法也可以...............!
12/15 09:38, 5F
文章代碼(AID): #1B8QVUP_ (GRE)
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文章代碼(AID): #1B8QVUP_ (GRE)