[問題] 愚昧的問一題 exam p samole Q43

看板CFAiafeFSA作者 (小豬)時間16年前 (2008/06/10 14:00), 編輯推噓2(205)
留言7則, 3人參與, 最新討論串1/1
可能是英文文法吧 最近做到 exam p 的sample 的第43題 A company takes out an insurance policy to cover accidents that occur at its manufacturing plant. The probability that one or more accidents will occur during any given month is 3/5. The number of accidents that occur in any given month is independent of the number of accidents that occur in all other months. Calculate the probability that there will be at least four months in which no accidents occur before the fourth month in which at least one accident occurs. 就是關於最後一句的翻譯 是在說"在第四個月至少有一次意外發生之前,最少有四個月沒有意外發生"嗎? 好像怪怪的說 看解答也看不出所以然 所以想請問板上有考過P的前輩們能夠幫忙解惑一下 如果能提供另外的作法就更感謝了 謝謝! -- 我是新手~ -- -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 124.8.143.71 ※ 編輯: a5170040 來自: 124.8.143.71 (06/10 14:01)

06/11 07:47, , 1F
七戰四勝制...沒發生意外贏...這題的英文很詭異 Orz
06/11 07:47, 1F

06/11 21:26, , 2F
沒記錯的話 就是你說的這樣 然後用negative binomial
06/11 21:26, 2F

06/11 21:28, , 3F
英文確是有點怪怪的 有時候真的很囧
06/11 21:28, 3F

06/11 21:29, , 4F
是geometry才對=.=
06/11 21:29, 4F

06/11 21:32, , 5F
去看了解答 發現negative才是對的 我在幹嘛=.=
06/11 21:32, 5F

06/27 22:22, , 6F
在第四個"意外月"發生前...有四個"非意外月"的機率..
06/27 22:22, 6F

06/27 22:22, , 7F
就是用 負二項分配來解囉~
06/27 22:22, 7F
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