In order to maintain its reputation for a high-quality product, sony wants to keep the standard deviation of the lifetimes of its tv’s below 1000 hours. a random sample of 24 tv’s is tested. in this sample, the standard deviation of tv lifetimes is 823 hours. assuming that the distribution of lifetimes of sony tv’s is approximately normal, test the null hypothesis that the standard deviation of their lifetimes is at least 1000 hours, against the alternative that it is less. use a 5% level of significance.

multiple choice #9 what is the form of the rejection region? a. reject h0 if s 2 < cv c. reject h0 if s 2 < cv1 or if s 2 > cv2 b. reject h0 if s 2 > cv d. reject h0 if s 2 = cv

multiple choice #10 (continued) when calculating the rejection region that controls the probability of type i error at 1%, the table value you need is the percentile of the random variable. a. 2.5th percentile; χ24 2 b. 97.5th percentile; χ23 2 c. 5 th percentile; χ23 2 d. 95 th percentile; χ24 2 multiple choice #11 (continued) without looking it up, what is the table value? (you can look it up, but you should not need to.) a. 35.17 b. 24 c. 23 d. 13.09

multiple choice #12 (continued) what is the value of cv (the critical value), in terms of s2 ? a. 13.09 c. 754.41 b. 842,965.2 d. 569,130.4

multiple choice #13 (continued) what is the conclusion of the test? a. accept h0 b. reject h0 in favor of ha