概率论,设X1,X2,X3为总体X的样本,T=X1+X2+CX3,则C=_______________时,T是E(X)的无偏估计.
问题描述:
概率论,设X1,X2,X3为总体X的样本,T=X1+X2+CX3,则C=_______________时,T是E(X)的无偏估计.
答
满足E(T)=E(X)
E(X1+X2+CX3)=E(X)
2E(X)+CE(X)=E(X)
(2+C)=1
C=-1