It is given that the sample statistic B is an unbiased estimator of the population parameter \(\alpha\).

Here, A and B are unbiased estimators of \(\alpha\). The standard deviations of A and B should be compared for deciding the best estimator of \(\alpha\). The best estimator of \(\alpha\) is the statistic that has the smaller standard deviation.

Here, A and B are unbiased estimators of \(\alpha\). The standard deviations of A and B should be compared for deciding the best estimator of \(\alpha\). The best estimator of \(\alpha\) is the statistic that has the smaller standard deviation.