设随机变量 X ~ E ( 5 ), 则 ((X)^2)=__________。设随机变量X~E(5),则__________。
设随机变量X~π(2),则D(X)=4。()A. 对B. 错
设随机变量X~B (5, 0.1),则D (1-2X )= 2 ( )A. 正确B. 错误
设X为随机变量,且E(X)=-1,D(X)=3,则E(3(X^2-2))=_____.设$$X$$为随机变量,且$$E(X)=-1,D(X)=3$$,则$$E(
设X为随机变量,则E(2X-3)=()A. $2EX$B. $4EX+3$C. $2EX+3$D. $2EX-3$
设离散型随机变量X的分布列为 (X=k)=dfrac (1)(5) ,=1, 2,3,4,5,则-|||-((X+2))^2= __
(7)设X为随机变量,且 E(X)=-1 ,D(X)=3 ,则 (2(X)^2-3)= __ .
设X为随机变量,则D(2X−3)=( ).A.2D(X)+3B.2D(X)C.2D(X)−3D.4D(X)设X为随机变量,则D(2X−3)=( ).A.2
10.设X,Y为随机变量,且 (X)=2, ((X)^2)=6, =2X+1, 则 D(Y)= ()-|||-A.9 B.8 C.5 D.4
设随机变量sim P(2)则 E ( X ) =_______, D ( X ) =__________ ,sim P(2)________.设随机变量则E(X