[理工] [商管]交大財金統計

[lyndonxxx (lyndon)]

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

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推 AF1:第一題用三項分配 X表二出現的次數 Y表三出現的次數
→ AF1:P(X=Y) = P(X=Y=0) + P(X=Y=1) + P(X=Y=2)
→ AF1:貝氏那題 我是寫令Yi表第i個樣本是否為不良品
→ AF1:Yi = 1 表第i個樣本為不良品  Yi = 0 表第i個樣本非不良品
→ AF1:取 n = 100 個樣本  寫出f(y1,y2,...,y100|x)然後和題目給的
→ AF1:f(x)相乘求出f(y1,y2,...,y100,x)  再對x積分可以得到
→ AF1:f(y1,y2,...,y100)  然後題目要求的分配就是f(x|y1,...,y100)
→ AF1:把兩個相除應該就是答案了@@
推 AF1:然後由題意 y1+...+y100 = 2
→ lyndonxxx:樓上應該榜首了
推 AF1:不可能  我統計頂多70@@
→ lyndonxxx:第一和第七你怎麼算 一我算11/36
推 AF1: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
→ lyndonxxx:七.(X1,..Xn)~U(0,θ) H0:θ≧4,H1<4, Yn=max{Xi}
→ lyndonxxx:拒絕域={Yn≦3.5} 求(a)power function,(b)size
→ sneak: 第一我把60抄成50計 https://daxiv.com