1.设X1,X2,···,xn来自总体X的样本, (X)=(sigma )^2, overline (X)=dfrac (1)(n)sum _(i=1)^n(X
4.设总体 sim N(mu ,(sigma )^2), x1,x2,···,xn为样本,证明 overline (x)=dfrac (1)(n)sum _(i
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) ,
5.11 设(X1,X2,···Xn, _(n)+1) 是正态总体N(μ,σ^2)的样本, overline (X)=-|||-dfrac (1)(n)sum
5.设x1,x2,···,xn是来自总体 sim N(mu ,(sigma )^2) 的样本,x为样本-|||-均值,令 =dfrac (sum _{i=1)^
设X1,X2,···,Xn是正态总体N(μ,σ^2 )的样本,则 dfrac (1)(n)sum _(i=1)^n(({X)_(i)-overline (X))
4.设X1,.,Xn为正态总体 sim N(mu ,(sigma )^2) 的样本,记 ^2=dfrac (1)(n-1)sum _(i=1)^n(({X)_(
12.设总体 sim N(mu ,(sigma )^2), μ,σ^2均未知,则 dfrac (1)(n)sum _(i=1)^n(({X)_(i)-overl
设X1,X2,···, _(n)(ngeqslant 2) 为来自总体N(μ,1)的简单随机样本,-|||-记 overline (x)=dfrac (1)(n
设总体 X sim N(mu, sigma^2), mu, sigma^2 均未知,则 (1)/(n) sum_(i=1)^n (X_i - overline(