作者smallpudding ( )
看板Statistics
标题[问题] 交大统研95机率论
时间Fri Mar 9 00:06:05 2007
※ [本文转录自 Grad-ProbAsk 看板]
作者: smallpudding ( ) 看板: Grad-ProbAsk
标题: [问题] 交大统研95机率论
时间: Fri Mar 9 00:05:01 2007
第二题：
Suppose {1,2,3,...,1000} is the finite population.
A sample of size 10 is drawn :
(a)if the sample is drawn
with replacement, what is the probability that
all 10 sample values are grater than 200 ?
(b)if the sample is drawn
without replacement, what is the probability that
all 10 sample values are grater than 200 ?
答案是(a)(8/10)^10
(b) 800
（ ）
10
-------
1000
（ ）
10
我不懂为什麽答案是这样....
()
谢谢～
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※ 发信站: 批踢踢实业坊(ptt.cc)
◆ From: 58.99.37.117
1F：推 logoer:with replacement == 取後放回...看成二项分布 03/09 10:08
2F：→ logoer:without replacement == 取後不放回...看成超几何分布 03/09 10:11
※ 编辑: smallpudding 来自: 59.125.37.194 (03/09 10:29)
3F：推 smallpudding:我不是要问黄色字..歹势误导大家了 ^^|| 03/09 10:29
4F：→ smallpudding:我了解了...原来是题目看错了>"< 英文太差Orz 03/09 10:35
5F：→ smallpudding:非常谢谢 03/09 10:36