Please show the solution step by step in details.

9.25 Suppose that Y1, Y2, . . . , Y\" denote a random sample of size n from a normal distribution with mean u and variance 1. Consider the rst observation Y1 as an estimator for 1.1.. (2 points) a Show that Y1 is an unbiased estimator for it. (2 points) '1 Find P(|Y1 it] E 1)- (1 point) t: Look at the basic denition of consistency given in Denition 9.2. Based on the result of part (b), is Y; a consistent estimator for ,u