9. (14%) Let X1,... , Xn be iid n(H,σ2), where σ2 is known. Show that the sample mean, T(X) = = (X1 + .. + Xn)/n, is a sufficient statistic forμ.

3. (10%) Suppose we are playing draw poker. We are dealt (from a well shuffled deck) 5 cards which contain 4 spades and another card of a different suite. We decide to discard the card of a different suite and draw one card from the remaining cards to complete a flush in spades (all 5 cards spades). Determine the probability of completing the flush.