关于这三个的感念

问题如下：

If the variance of the sampling distribution is smaller than that for other estimators of the parameter, the estimator is ：

选项：

A.

unbiased

B.

efficient.

C.

consistent.

解释：

B is correct, for all unbiased, estimators, if the sampling dispersion is smaller than any other unbiased estimators, then this unbiased estimator is called efficient.

对于所有无偏估计量，如果样本的离散度小于任何其他无偏估计量，则改样本的无偏估计量是有效的。