题目内容
若随机变量~,且=0.1587,则__________.
0.8413
已知随机变量x服从正态分布,且=0.9544,
=0.6826,若=4,=1,则P(5<x<6)=( )
A.0.1358 B.0.1359 C.0.2716 D.0.2718
若随机变量X服从二点分布,且成功的概率p=0.5,则E(X)和D(X)分别为( )
(A)0.5和0.25 (B)0.5和0.75
(C)1和0.25 (D)1和0.75