Given the following densities, find sufficient statistics for the parameters if there are any. a. f(x; r, 2 ) = x' e"Ax I (0.0.) (x) ; r > 0, a >0 [(r) b. f ( x; 1, 6 2 ) = e 202 ( X-H) 2 ;-00 0 OV2T 0 c. f(x; 0) = (1 +x) 1+0 ; X >0 , 0>0