x
3
4
5
6
7
8
y
4.0
2.5
﹣0.5
0.5
﹣2.0
﹣3.0
均为偶数”,则P(B|A)=( )
30,42,41,36,44,40,37,37,25,45,29,43,31,36,49,34,33,43,38,42,32,34,46,39,36.
根据上述数据得到样本的频率分布表如下:
分组
频数
频率
[25,30]
0.12
(30,35]
0.20
(35,40]
0.32
(40,45]
n1
f1
(45,50]
n2
f2