Can you help me with this question. It is taken from Statistical Inference, Berger and Casella.

7.19 Suppose that the random variables Y1, . . ., Yn satisfy saismax! ni mmos avail ow doddw ,6:TDS ad naa uondinilob aidT . Yi = Bri +ei, i= 1, . . ., n, 31 ) el sesD bne wood Of.T at boritob al opens e sads lapofl . Ta.. van yd where T1, ..., In are fixed constants, and 61, . . ., En are iid n(0, 0?), o' unknown. (6=) (a) Find a two-dimensional sufficient statistic for (3, 62). oftom uounitnoo bamof (b) Find the MLE of /, and show that it is an unbiased estimator of S.( eidy d(c) Find the distribution of the MLE of B. no ,a tadi coldarum