,n) ,则-|||-由切比雪夫不等式,有 (|dfrac (1)(n)sum _(i=1)^n({X)_(i)}^2-(mu )_(2)|geqslant c
(B) dfrac (1)(n+1)sum _(i=1)^n(({X)_(i)-overline (X))}^2 .-|||-(C) dfrac (1)(n)s
({S)_(n)}^2=dfrac (1)(n-1)sum _(i=1)^n((x)_(i)--|||-(x))^2 是样本方差,试求满足 (dfrac ({{
dfrac (1)(n-1)sum _(i=1)^n(({X)_(i)-overline (X))}^2 .-|||-n-|||-C. sqrt (dfrac
,(X)_(n+1))(ngt 1) 取自总体 sim N(mu ,(sigma )^2) , overline (X)=dfrac (1)(n)sum _(i
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
,(x)_(n),(x)_(n+1) 是来自N(μ,σ^2)的样本, overrightarrow ({x)_(n)}=dfrac (1)(n)sum _(i=
,(X)_(n+1))(ngt 1) 取自总体 sim N(mu ,(sigma )^2) . overline (X)=dfrac (1)(n)sum _(i
设随机变量 X sim N(mu, sigma^2),利用切比雪夫不等式估计 P|X-mu|A. $\leq \frac{1}{9}$;B. $\geq \fr
1.6 总体X-N(mu,sigma^2),x_(1),x_(2),...,x_(n)为其样本,bar(x)=(1)/(n)sum_(i=1)^nx_(i),s