5. Refer to the setup described in CB's Exercise 6.37. 6.37 Joshi and Nabar (1989) examine properties of linear estimators for the parameter in the so-called "Problem of the Nile," where (X, Y) has the joint density f(x,y) = exp(-(0x+y/0)}, > 0, y>0. Below are the Estimators T- and U- (a) Show that S (EXY) is minimal sufficient (b) Set W (T,U), where T and U are as defined CB's Exercise 6.37. Show that W is minimal sufficient. Hint: A one-to-one function of a minimal sufficient statistic is minimal sufficient. (c) Show that U is an ancillary statistic. (d) Why does U being ancillary imply W is not complete?