设随机变量X~N(1,4),已知Φ(0.5)=0.6915,则P{1≤x≤2}

问题描述:

设随机变量X~N(1,4),已知Φ(0.5)=0.6915,则P{1≤x≤2}

P{1≤x≤2}=P{0≤(x-1)/2≤0.5}=Φ(0.5)-Φ(0)=0.6915-0.5=0.1915