设X~N(10,1),则有( )成立。A.P(5P(5.5B.P(9C.P(3D.P(x>10)11)
点击查看答案
设随机变量X和Y相互独立,且X~N(2,42),Y~N(3,92),则D(X+Y)=()
设随机变量和是相互独立的随机变量且都服从正态分布,X~N(3,4),Y~N(2,9),求D(3X+4Y)=()
设X~N(10,1),则有( )成立。A.P(5<X<6)>P(5.5<X<6.5)B.P(9<X<10)=P(10<X<11)C.P(3<X<10)<P(8<X<9)D.P(x>10)<P(x>11)
设X~N(9,3p>2p>),Y~N(5,0.5p>2p>),则有()成立。A.P(6P(4.5设X~N(9,3p>2p>),Y~N(5,0.5p>2p>),则有( )成立。A.P(6<X≤15)>P(4.5<Y≤6)B.P(6<X≤15)<P(4.5<Y≤6)C.P(6<X≤15)=P(4.5<Y≤6)D.P(6<X≤15)>2P(4.5<Y≤6)
设随机变量X~t(n)(n>1),则(54)。A.Y~x2(n)B.Y~x2(n-1)C.Y~F(n,1)D.Y~F(1,n)
等式[x]补+[Y]补=[x+Y]补在满足条件(92)时成立,其中X、Y是用n个二进制位表示的带符号纯整数。A.-2n≤(X+Y)≤2n-1B.-2n-1≤(X+Y)<2n-1C.-2n-1-1≤(X+Y)≤2n-1D.-2n-1≤(X+Y)<2n