Let X1,X2,...,X be an independent random variables of size n from a normal population with the unknown mean it and known variance 0-2 =16. We wish to test the hypothesis Ho .' ,u =10 versus Hl :p =15. 3) Find the best critical region for testing the above hypothesis. (8 marks) b) What is the minimum sample size for the hypothesis such that both type I and type II error are both equal to 0.05. (8 marks) c) if the sample size taken is 25 and the signicance level is 0.05. obtain the best critical region in part a). (4 marks)