[理工] [商管]交大財金統計

看板Grad-ProbAsk作者 (lyndon)時間14年前 (2012/02/20 16:26), 編輯推噓4(4推 0噓 12→)
留言16則, 3人參與, 最新討論串1/1
If five balance dice are rolled, what is the probability that the number 2 and the number 3 will appear the same number of times? 我是算1/6 不過好像想的太簡單了 Suppose that the proportion x of defective items in a large shipment is unknown, and that the prior distribution of x is a beta distribution for which the parameter are a=3 and b=150. If 100 items are selected at random from the shipment and if two of these items are found to be defective, what is the posterior distribution of x? 這題想不出來,他己經給了Beta分配的參數,所以後驗會一樣嗎?對貝氏不是很熟XD -- posted from android bbs reader on my HTC Hero https://market.android.com/details?id=com.bbs.reader -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 221.120.6.92
推
02/21 21:27, , 1F
第一題用三項分配 X表二出現的次數 Y表三出現的次數
02/21 21:27, 1F
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02/21 21:28, , 2F
P(X=Y) = P(X=Y=0) + P(X=Y=1) + P(X=Y=2)
02/21 21:28, 2F
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02/21 21:37, , 3F
貝氏那題 我是寫令Yi表第i個樣本是否為不良品
02/21 21:37, 3F
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02/21 21:37, , 4F
Yi = 1 表第i個樣本為不良品 Yi = 0 表第i個樣本非不良品
02/21 21:37, 4F
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02/21 21:39, , 5F
取 n = 100 個樣本 寫出f(y1,y2,...,y100|x)然後和題目給的
02/21 21:39, 5F
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02/21 21:40, , 6F
f(x)相乘求出f(y1,y2,...,y100,x) 再對x積分可以得到
02/21 21:40, 6F
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02/21 21:41, , 7F
f(y1,y2,...,y100) 然後題目要求的分配就是f(x|y1,...,y100)
02/21 21:41, 7F
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02/21 21:41, , 8F
把兩個相除應該就是答案了@@
02/21 21:41, 8F
推
02/21 21:44, , 9F
然後由題意 y1+...+y100 = 2
02/21 21:44, 9F
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02/22 16:22, , 10F
樓上應該榜首了
02/22 16:22, 10F
推
02/22 18:45, , 11F
不可能 我統計頂多70@@
02/22 18:45, 11F
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02/23 15:22, , 12F
第一和第七你怎麼算 一我算11/36
02/23 15:22, 12F
推
02/23 17:02, , 13F
第一我把60抄成50計算錯...11/36應該沒錯 第七我忘記題目了
02/23 17:02, 13F
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02/23 18:08, , 14F
七.(X1,..Xn)~U(0,θ) H0:θ≧4,H1<4, Yn=max{Xi}
02/23 18:08, 14F
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02/23 18:09, , 15F
拒絕域={Yn≦3.5} 求(a)power function,(b)size
02/23 18:09, 15F
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09/11 14:57, , 16F
第一我把60抄成50計 https://daxiv.com
09/11 14:57, 16F
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