若
独立,则
()
A.对
B.错
若
独立,则
()
A.对
B.错
若 Y=X_(1)+X_(2),X_(i) sim N(0,1),i=1,2,则()A. $E(Y)=0$;B. $D(Y)=2$;C. $Y \sim N(0
设sim N(1,2),sim N(1,2),且X与Y相互独立,则sim N(1,2)________.设,,且X与Y相互独立,则________.
判断题-|||-已知 sim N(0,1), sim N(1,1), 相互独立,则-|||--y 服从 (-1,2).-|||-A.对-|||-B.错
设总体sim N(0,1) ,X1,X2,···X5为来自总体的样本,令sim N(0,1) ,X1,X2,···X5则下列说法错误的是( )sim N(0,1
设 sim N(0,1) ,求:(1) =(X)^2;
样本 X_1, X_2, ldots, X_n 来自总体 X sim N(0,1) , overline(X) = (1)/(n) sum_(i=1)^n X_
X,Y独立, sim N(0,1) , sim N(1,1), 则 () .-|||-? DACB
设X与Y相互独立,且approx N(1,2), _(Delta )N(0,1),令approx N(1,2), _(Delta )N(0,1),则D(Z) =
4.样本X1,X2,···Xn来自总体 sim N(0,1) , overline (X)=dfrac (1)(n)sum _(i=1)^n(X)_(i) ,
设Xi ~ N(0 , 4), i =1, 2, 3, 且相互独立, 则 ( ) 成立。A.dfrac ({X)_(1)}(4)sim N(0,