| 以文本方式查看主题 - SCI论坛 (http://cqsiam.cn/scibbs/index.asp) -- 精算师沙龙 (http://cqsiam.cn/scibbs/list.asp?boardid=33) ---- 有人会做这道题吗 (http://cqsiam.cn/scibbs/dispbbs.asp?boardid=33&id=4193) |
| -- 作者：小鱼儿andy -- 发布时间：2004/11/17 23:02:33 -- 有人会做这道题吗 identical twins come from the same egg and hece are of the same sex.fraternal twins have a 50-50 chace of being of the same sex.among twins,the probobility of a fraternal set is p and an indentical set is q=1-p.if the next set of twins are of the same sex,what is the probobility that they are identical 答案是2q/(1+q) 有没有人可以先帮我翻译一下,再大概告诉我大致思路 |
| -- 作者：jujuwaugh -- 发布时间：2004/11/18 9:44:22 -- 实际上就是Bayes公式的应用,同卵双胞胎同性概率为1，异卵同性概率为1/2，而异卵双胞胎的概率是p，同卵概率是q＝1－q。求在同性的情况下，同卵的概率是？ 记A为同性事件，B为同卵事件，所求P（B|A）＝P(A|B)*P(B)/[P(A|B)*P(B)+P(A|B\' )*P(B\' )] |