In a certain community, 36% of the families own a dog and 22% of the families that
own a dog also own a cat. In addition, 30% of the families own a cat. What is
(a) the probability that a randomly selected family owns both a dog and a cat;
(b) the conditional probability that a randomly selected family owns a dog given that it owns a cat?
thx for ur ans
統計學問題.....有點難...
2008-11-24 11:44 pm
回答 (2)
2008-11-25 7:58 am
✔ 最佳答案
Let C be the event that a randomly selected family owns a catLet D be the event that a randomly selected family owns a dog
Pr (C) = 0.3
Pr (D) = 0.36
Pr (C AND D) = 0.22
a)
Pr (C AND D) = 0.22
b)
Pr (D | C) = Pr (C AND D) / Pr (C) = 0.22 / 0.3 = 11 / 15
2008-11-25 12:06 am
(a)
P(dog and cat)
= 36% x 22%
= 7.92%
(b)
P(dog | cat)
= P(dog and cat) / P(cat)
= 7.92% / 30%
= 26.4%
=
P(dog and cat)
= 36% x 22%
= 7.92%
(b)
P(dog | cat)
= P(dog and cat) / P(cat)
= 7.92% / 30%
= 26.4%
=
收錄日期: 2021-04-23 23:05:03
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20081124000051KK00832