2. A quality control engineer finds that a sample of 100 light bulbs had an average life time of 470 hours. Assuming a populatio
n mean of 480 hours with standard deviation of g = 25 hours. Test whether data indicates the mean life time of bulbs is less than 480 hours at 5% level of significance. a). Write down all the details given in the problem [2 points] b). State the hypotheses [6 points] c). Find the critical value and draw in on a bell curve [2 points] d). Calculate the test statistic [5 points] e). Find p-value [4 points] f). What is your decision? [2 points] g). Interpret your decision in context of the problem. [4 points]
