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)=0.8413-|||-(1)求灯管寿命在 -1200 小时的概率;-|||-(2)若规定寿命不低于900小时的灯管为一级品,求一支灯管是一级品的概率。I

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

1党的最终目标是()circled 1 circled 2 circled 3 1党的最终目标是()\textcircled 1 \textcircled 2

返混带来的最大影响是circled 1 circled 2 circled 3 circled 4 返混带来的最大影响是\textcircled 1 \tex

已知X~N(1,4)，则P |X-1| leq 2 =______Phi(1)=0.8413，Phi(2)=0.977236.（1.6分）已知X~N(1,4)，

( 注 : Φ(1) = 0.8413,Φ(2) = 0.9772约等于0.977 )A. 0.2267B. 0.3896C. 0.4632D. 0.6826

5.求极限lim_(ntoinfty)(1+(1)/(n^2))(1+(2)/(n^2))...(1+(n)/(n^2)).5.求极限$\lim_{n\to\i

2高等学校学生安全教育及管理,要以预防为主,应本着()的原则circled 1教管结合circled 2教育先行[1]circled 3妥善处理circled

属于半标准货物系固设备的有_。circled 1系固槽座; circled 2快速释放紧索器; circled 3象脚; circled 4绑扎带; circl

4.设Xsim N(3,2^2)，试求：(1)P(X<5)；(2)P(X>9).(已知Phi(1)=0.8413,Phi(2)=0.9772,Phi(3)=0.

垫料的厚度取决于()。circled 1连接面之间的间隙; circled 2预紧力; circled 3连接面的面积;circled4表面粗糙度; circl