設(shè)總體X~N(0,1),X1,X2,...,Xn為簡(jiǎn)單隨機(jī)樣本,問(wèn)統(tǒng)計(jì)量服從什么分布?
A.z1-a(n)-za(n) B.χ21-a(n)=-χ2a(n) C.t1-a(n)=-ta(n) D.F1-a(n1,n2)=1/Fa(n1,n2)
設(shè)總體X任意,期望為μ,方差為σ2,若至少要以95%的概率保證|-μ|〈0.1σ,問(wèn)樣本容量n應(yīng)取多大?