the variance, which has smaller mean squared error (MSE) than the unbiased estimator S 2.
In this work, the estimator S 2 1= c 1 S 2, c 1= n (n− 1)[n (n− 1)+ 2]− 1, is constructed and is
shown to have the following properties:(a) it has smaller MSE than S 2 2, and (b) it cannot be
improved in terms of MSE by an estimator of the form cS 2, c> 0. The method of construction
is based on Stein's classical idea brought forward in 1964, is very simple, and may be taught …