是这样的 这题是交大98统研机率论第一题 因为同一个老师解了不同版本(成大93年有考过) 所以想请教各位 拜托了.... 题目↓↓ A judge is 65% sure that a suspect has committed a crime. During the course of the trial a witness convinces the judge that there is an 85% chance that the criminal is left-handed. If 23% of the population is left-handed and the suspect is also left-handed, with this new information, how certain should the judge be of the guilt of the suspect? 其实是我不太懂他要求什麽>"< 版本一：题给P(判定嫌犯有罪)=0.65 所求=P(左嫌│有罪)=(0.23*0.85)/0.65=0.301 版本二： 0.85 / 罪 0.23 左 0.15 \ 无罪 a / 1-a \ b / 罪 右 1-b \ 无罪 a = 0.23/0.85 = 0.27 b = (0.65-0.73)/0.73= 0.58 所求 = 0.27*0.85+0.73*0.58 = 0.6525 请问哪一个才是对的?? 还是两个都不对呀?? 因为同学和学长都说好像都不对 却解不出来>"< 拜托请求好心人帮我解答^^ --

※ 发信站: 批踢踢实业坊(ptt.cc) ◆ From: 61.64.114.65 ※ 编辑: ivy750910 来自: 61.64.114.65 (01/20 23:30)