多项选择题
A.设X~N(μ,σ2),则u=(X-μ)/σ~N(0,1) B.设X~N(μ,σ2),则对任意实数a、b有P(X<=Ф[(b-μ)/σ) C.设X~N(μ,σ2),则对任意实数a、b有P(X>=1-Ф[(a-μ)/σ] D.设X~N(μ,σ2),则对任意实数a、b有P(a<X<=Ф[(b-μ)/σ)-Ф[(a-μ)/σ] E.设X~μ(μ1,,Y~N(μ2,,则X+Y~N(μ1+μ2,(σ1+σ2) 2)
A.E(XD)=6 B.B(XD)=8 C.σ(XD)=0.1225 D.σ(XD)=0.1414 E.σ(XD)=0.324