confidence interval estimate for the population variance. the most student loan 11-41. A medical research group is investigating what 2015.) Suppose rando differences might exist between two pain-killing drugs, students and 205 Citac Azerlieve and Zynumbic. The researchers have already standard deviations of established there is no difference between the two drugs Using an alpha level of in terms of the average amount of time required before the standard deviations they take effect. However, they are also interested in universities are equal. knowing if there is any difference between the variability of time until pain relief occurs. A random sample of Computer Software E 24 patients using Azerlieve and 32 patients using 11-45. Suppose the California Zynumbic yielded the following results: a study on a stretch of i Francisco to determine Azerlieve Zynumbic in driving speeds of cars licensed out of state. On nA = 24 nz = 32 was whether there was a SA - 37.5 seconds $z - 41.3 seconds driving speeds for Califo data file Speed-Test con Based on these sample data, can the researchers selected California cars conclude a difference exists between the two drugs? out-of-state cars. Based 11-42. The Littleton Corporation manufactures high-speed you conclude at the 0.05 electronic cables and focuses on products for the there is a difference betwct the null ypothesis b. Describe a Type II error in the context of this exercise. d exactly 11-43. Soft drink bottling companies such as Coca-cola use pt that quality-control techniques to assure that the average here amount of cola in the cans is 12 ounces. Suppose that a ated test small standard deviation of 0.05 ounce is acceptable. Any significant difference from this standard deviation would reflect badly on the quality-control measures mpany has concerning the average amount of cola in the 12-ounce its used in cans. A sample of size 20 indicated that the standard deviation was 0.070. is concerned a. Determine if the standard deviation of the amount of the cooking cola in the cans differs from the standard deviation onsistency specified by the quality control division. Use a sample of 27 significance level of 0.10. the b. The quality-control sampling occurs several times only a point a day. In one day, seven samples were taken, and sted a 98% three indicated that the standard deviation was not tion variance 0.05. If the seven samples were taken at a time in which the standard deviation met specifications, s. Maher's determine the probability of having at least three out ange in the of seven samples indicate the specification was not -end seat. being met. The 2013 graduating class from St. Francis University in
