推 locust0923:謝謝!!P(嫌疑犯是左撇子|嫌疑犯不是兇手) = 0.23這地方 02/02 23:42
→ locust0923:我想錯了....以為題目給的是全部人左撇子的機率...= = 02/02 23:43
→ locust0923:非常感激你的回答!! 02/02 23:43
※ 引述《locust0923 (檸檬優酪乳)》之銘言：
: 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 crimianl is left-handed .If 23% of the population is left-handed and
: the suspect is also left-handed, with this new information, how certain
: shoud the judge be of the guilt of the suspect?
: 大概知道它是要求條件機率，不過感覺給的條件不是很夠
: 大概是我的題目理解差....希望有高手人幫忙一下
: 給個提示也可以，給個想法也可以，感激!!
P(嫌疑犯是兇手) = 0.65
P(嫌疑犯不是兇手) = 0.35
P(嫌疑犯是左撇子|嫌疑犯不是兇手) = 0.23
P(嫌疑犯是左撇子|嫌疑犯是兇手) = 0.85
0.65*0.85 1105
P(嫌疑犯是兇手|嫌疑犯是左撇子) = ---------------------- = ----------
0.35*0.23 + 0.65*0.85 1266
應該是這樣吧，有錯請指正
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