Center A Center B 97 64 95 85 89 72 79 64 78 74 87 93 83 70 94 79 76 79 79 75 83 66 84 83 76 74 82 70 85 82 85 82 91 75 72 78 86 99 70 57 91 91 82 78 73 87 96 93 64 89 74 81 88 84 88 63 60 78 73 66 84 85 85 84 59 62 91 83 80 76 Use the tutorial on page 442 appendix 10.3 z-Test: Two Sample for Means Section 10.1 in the text alpha 0.05 Mean 78 Known Variance 100 Observations 30 Hypothesized Mean Difference 0 z -1.656157 P(Z<=z) one-tail 0.048845 z Critical one-tail 1.6449 P(Z<=z) two-tail 0.0977 z Critical two-tail 1.9600 margin of error 4.733763 ci upper 0.733763 ci lower -8.733763 82 100 40 anufactuere 1 Manufactuere 2 684 831 859 893 922 939 972 1016 697 835 860 899 924 943 977 1041 720 848 868 905 926 946 984 1052 773 852 870 909 926 954 1005 1080 821 852 876 911 938 971 1014 1093 819 907 952 994 1016 1038 1096 1153 836 912 959 1004 1018 1072 1100 1154 888 918 962 1005 1020 1077 1113 1174 897 942 986 1007 1022 1077 1113 1188 903 943 992 1015 1034 1082 1116 1230 Use the data analysis tool or template to answer the questions A consumer group wants to determine if there is any difference in the average life of two light bulbs. They have collected samples from each manufacturer. The population variance for manufacturer 1 is known to be 8836 while the population variance for namufacturer 2 is kno a b c d Establish the null hypothesis to determine if the difference between the two manufacturers. What is your decision regarding the null hypothesis? Use the p value to justify your decision. Calculate a 95% confidence interval and explain why it does or does not support your conclusion. now to be 9216\\ bank1 4.21 5.55 3.02 5.13 4.77 2.34 3.54 3.2 4.5 6.1 0.38 5.12 6.46 6.19 3.79 bank2 9.66 5.9 8.02 5.79 8.73 3.82 8.01 8.35 10.49 6.68 5.64 4.08 6.17 9.91 5.47 10.15 berenson A bank with a branch located in a commercial district of a city has developed an improved process for serving customers during the noon to 1 pm lunch period. The waiting time of all customers during this hour is recorded over a period of one week. A random sample of 15 customers is reported as bank1 Suppose that another branch located in a residential area is also concerned with the noon to 1 pm lunch period. Assume the population variances for bank1 is 2.68 and the variance for bank2 is 4.34 a b c Is there evidence of a difference in the mean waiting times? (alpha=.05) Explain your decision regarding the null hypothesis using the p value to justify your answer. Construct and interpret a 95% confidence interval. Explain why it supports your answer from b. loc1 1.48 1.75 0.78 2.85 0.52 1.6 4.15 3.97 1.48 3.1 1.02 0.53 0.93 1.6 0.8 1.05 6.32 3.93 5.45 0.97 loc2 7.55 3.75 0.1 1.1 0.6 0.52 3.3 2.1 0.58 4.02 3.75 0.65 1.92 0.6 1.53 4.23 0.08 1.48 1.65 0.72 a b c 10.17 A problem with a telephone line that prevents a customer from receiving or making calls is disconcerting to bot the customer and the telephone company. The data report the time to clear these customer line problems (in minutes) for two different telephone offices. Assume the population variances are known and loc1 is 1.7 and loc2 is 1.89, Establish the hypothesis to determine if there is a difference in the mean time between the two offices? (alpha Explain your decision regarding the null hypothesis using the p value. Construct and interpret a 95% confidence interval and explain why it does or does support your null hypothesis conclusion. ha=.05) train-comptrain-team 19.4 22.4 16.7 13.8 20.7 18.7 19.3 18 21.8 19.3 16.8 20.8 14.1 15.6 17.7 17.1 16.1 18 19.8 28.2 16.8 21.7 19.3 20.8 14.7 30.7 16 24.7 16.5 23.7 17.7 17.4 16.2 23.2 17.4 20.1 16.4 12.3 16.8 15.2 18.5 16 10.20 a b c The director of training for an electronic equipment manufacturer is interested in determining whether different training methods have an effect on the productivity of assembly-line employees. She randomly assigns 42 recently hired employees into two groups of 21. The first group received a computer assisted, individual based training program and the other receives a team based training program. Upon completion of the training, the employees are evaluated on the time (in seconds) it takes to assemble a part. Assume the variances in the populations of training methods are know and equal to 4. Is there evidence of adifference between the mean assembly times (in seconds) of the two types of employees (alpha=.01 Establish the null hypothesis and explain whether or not you are rejecting the null hypothesis using the critical value Construct a 95% confidence interval and explain how it does or does not support your null hypothesis decision. 01)