设随机变量backsim N(2,9), circled (1)(0.5)=0.6915 circled (p)(1)=0.8413，则backsim N(2,9), circled (1)(0.5)=0.6915 circled (p)(1)=0.8413_________;backsim N(2,9), circled (1)(0.5)=0.6915 circled (p)(1)=0.8413_________.

设随机变量sim N(2,9)，则sim N(2,9)（）设随机变量，则（）A.B.C.D.

设随机变量 sim N(2,9)，则sim N(2,9)A.对B.错设随机变量，则A.对B.错

5.某型号的灯管寿命(以小时计) backsim N(1000,(100)^2) (circled (1)(2)=0.9772 circled (1)(1)=0

随机变量X～N(2，9)，则(X-2)/3～()A. N(2，9)B. N(0，9)C. N(0，1)D. N(2，3)

3) 设随机变量X服从正态分布N(2,9),则P(X<5)=____。3) 设随机变量X服从正态分布N(2,9),则P(X<5)=____。

1.设随机变量 backsim B(6,dfrac (1)(2)), 则 P(X=3) 等于 ()-|||-

设随机变量 X sim N(1,9)，则 P|1A. $\Phi(4) - \Phi(1)$B. $\Phi(1) - 0.5$C. $\Phi\left(\f

设随机变量 X sim N(1,9), 则 P|1A. $\Phi\left(\frac{1}{3}\right)$B. $\Phi\left(\frac{1}

已知随机变量X与Y相互独立且backsim N(1,2), approx N(-2,1),则backsim N(1,2), approx N(-2,1),服从的

【题目】设随机变量X~N(2,4),则 P(X≤0)= 附(1)=0.8413【题目】设随机变量X~N(2,4),则 P(X≤0)= 附(1)=0.8413