概率论题目,设随机变量X-b(3,1/3),则P{X>1}=
问题描述：
概率论题目,设随机变量X-b(3,1/3),则P{X>1}=
答
P{x>1}=1-P{X=1}-P{X=0}
=1-[1-(1/3)]^3-C(1,3)*(1/3)*[1-(1/3)]^2
=1-(8/27)-(12/27)
=7/27