Verify that the permutation group, given in Example 6, is indeed a group of transformations. Verify that  are groups of transformations of e and d, respectively. Assume that   is known, and that it is...

Verify that the permutation group, given in Example 6, is indeed a group of transformations.

Verify that
 are groups of transformations of e and d, respectively.

Assume that
  is known, and that it is desired to estimate
 under loss

Find the best invariant estimator of
.