CAN YOU PLEASE GIVE THE DETAILED EXPLANATION AND SOLVE IT IN EXCEL , THANK YOU !!

(a) We would like to demonstrate that the mean shelf life exceeds 120 days. Set up appropriate hypotheses for investigating this claim. (b) Test these hypotheses using a = 0.01. What are your conclusions? (c) Find the P-value for the test in part (b). (d) Construct a 99 percent confidence interval on the mean shelf life.\f2.20 Consider the shelf life data in Problem 2.19. Can shelf life be described or modeled adequately by a nor- mal distribution? What effect would the violation of this assumption have on the test procedure you used in solving S Problem 2.15? 2.21 The time to repair an electronic instrument is a nor- mally distributed random variable measured in hours. The repair times for 16 such instruments chosen at random are as follows: Hours 159 280 101 212 224 379 179 264 222 362 168 250 149 260 485 170 (a) You wish to know if the mean repair time exceeds 225 hours. Set up appropriate hypotheses for investigating this issue. (b) Test the hypotheses you formulated in part (a). What are your conclusions? Use a = 0.05. (c) Find the P-value for the test. (d) Construct a 95 percent confidence interval on mean repair time.2.22 Reconsider the repair time data in Problem 2.21. Can repair time.' in your opinion, be adequately modeled by a nor- nc-i ma] distribution