Question 6 Not yet answered Points out of 1.00 Flag question The owner of a local nightclub has recently surveyed a random sample of n = 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd. If not, no entertainment changes will be made. The appropriate hypotheses to test are Select one: Qa. HD : H 2 30 versus H1 : p 30. OC HO: X BAR S 30 versus HI : X BAR > 30. Question 7 Not yet answered Points out of 1.00 P Flag question The owner of a local nightclub has recently surveyed a random sample of n= 250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to an older crowd, If not, no entertainment changes will be made. If she wants to have a level of significance at 0.01, what rejection region should she use? Select one: Oa. Reject HO if t 2 3263. Question 8 Not yet answered Points out of 1.00 P Flag question A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors results in 83 who indicate that they recommend aspirin. The value of the test statistic in this problem is approximately equal to Select one Oa. -4.12. Ob. -2.33 OC -1.86. Question 9 Not yet answered Points out of 1.00 P Flag question A manager of the credit department for an oil company would like to determine whether the mean monthly balance of credit card holders is equal to $75. An auditor selects a random sample of 100 accounts and finds that the mean owed is $83 40 with a sample standard deviation of $23.65. If you wanted to test whether the mean balance is different from $75 and decided to reject the null hypothesis, what conclusion could you reach? Select one: Oa. There is no evidence that the mean balance is $75. Ob. There is evidence that the mean balance is not $75. Oc. There is evidence that the mean balance is $75