单选题
Using the following joint probability distribution to answer the following question.
If you know that Y is equal to 2, the probability that X is equal to 1 is closest to:
A
0.05
B
0.25
C
0.20
D
0.17
平均正确率:73.1%
正确答案:D你的答案:
解析
P(X = 1|Y = 2) = 0.05/(0.05 + 0.10 + 0.15) = 0.17老师这道题如果用公式应该是p(x=1|y=2)=p(y=2|x=1)p(x=1)/p(y=2),为何答案没有分子中p(x=1)部分?