1 设总体Xsim N(0,1)，X_(1),X_(2),...,X_(n)为X的样本，则((X_(1)-X_(2))/(X_(3)+X_{4)})^2服从__
设X_(1),X_(2),...,X_(n)为总体Xsim N(mu,sigma^2)的样本，证明hat(mu)_(1)=(1)/(2)X_(1)+(2)/(3
14.[填空题]设X_(1),...,X_(6)为总体Xsim N(0,1)的一个样本，且cY服从chi^2分布，这里，Y=(X_(1)+X_(2)+X_(3)
设X_(1),X_(2)...,X_(n)是来自总体X的样本，则(1)/(n-1)sum_(i=1)^n(X_(i)-overline(X))^2为(）.A.
(45)设数列x_{n)}满足x_(1)=1,x_(n+1)=(x_(n)+2)/(x_(n)+1)(n=1,2,...),试证lim_(ntoinfty)x_
设X_(1),X_(2),...,X_(n)是来自总体X的样本，则(1)/(n-1)sum_(i=1)^n(X_(i)-overline(X))^2是（）A.
8.设总体X的概率密度为f(x)，X_(1),X_(2),...,X_(n)为来自X的样本，x_(1),x_(2),...,x_(n)为样本值，则样本的联合概率
设数列x_{n)}满足：x_(1)>0,x_(n)e^x_(n+1)=e^x_(n)-1(n=1,2,...).证明x_{n)}收敛，并求极限lim x_(n)
4.(1)设样本X_(1),X_(2),...,X_(6)来自总体N(0,1),Y=(X_(1)+X_(2)+X_(3))^2+(X_(4)+X_(5)+X_(
7.设X_(1),X_(2),X_(3)是来自总体Xsim N(0,1)的一组样本，则X_(1)+X_(2)+X_(3)：____，X_(1)^2+X_(2)^