推 Jautism:我覺得L|A才是0.85 04/06 17:54
→ jasonkeen:好像是耶，還好沒考 XD 04/06 18:13
推 brucejune:感謝樓上兩位大大^^" 04/06 22:58
※ 編輯: jasonkeen 來自: 140.114.36.74 (01/21 23:16)
※ 引述《brucejune (...)》之銘言：
A judge is 65% sure that a suspect has committed a crime.
P(A)=0.65
P(B)=0.35
A,B 為補集合
During the course of the trial a witness convinces the judge that there is
an 85% chance that the criminal is left-handed.
P(L|A)=0.85
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?
P(L)=0.23
P(A|L)=P(L|A)*P(A)/( P(L|A)*P(A) + P(L|B)*P(B) )
=0.85*0.65/(0.85*0.65+0.23*0.35)=0.873
--
可能我想的太簡單了，沒記錯的話這題20分，有錯請指正…
--
Artists use lies to tell the truth,
while politicians use them to cover the truth up.
V for Vendetta - V怪客
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.114.34.182