X and Y are random sample from a population with mean mu and variance sigma squared. (assume that X and Y are indeoendently distributed).

Consider the following two point estimators of the population mean.

1)0.31X+ 0.69Y

2)0.37X+ 0.63Y

(both estimators should be unbiased.

Question is find the relative effiency:

THe formula is

Var (theta2)

-----------

Var (theta 1)

I would appreciate yourhelp.