设随机变量X~N(1,σ^2),且P(0
问题描述:
设随机变量X~N(1,σ^2),且P(0
答
P(0
Φ(-1)=2*0.8-1=0.4
P(X>0)
=P((x-1)/σ>-1)
=1-Φ(-1)
=0.6