STATISTICS

Answer the given problem. Analyze what tool should be used.

1. Does coffee or some other form of simulation really allow a person suffering from alcohol intoxification to "sober up"? A sample of 44 healthy male students participated in the experiment. Each student was asked to memorize a list of 40 terms (20 terms on a green list and 20 terms on a red list). The students were then randomly assigned to one of four different treatment groups (11 students in each group). Students in three of the groups were each given two alcoholic beverages to drink prior to performing a work completion task. Students in Group A received only the alcoholic drinks. Participants in Group AC had caffeine powder dissolved in their drinks. Group AR participants received a monetary award for correct responses on the word completion task. Students in Group P (the placebo group) were told that they would receive alcohol, but instead received two drinks containing a carbonated beverage (with a few drops of alcohol on the surface to provide an alcoholic scent). After consuming their drinks and resting for 25 minutes, the students performed the word completion task. Their scores (simulated on the basis of summary information from a certain article) are reported in the table. (Note: A task score represents the difference between the proportion of correct responses on the green list of words and the proportion of incorrect responses on the red list of words.)

AR	AC	A	P
0.51	0.50	0.16	0.58
0.58	0.30	0.10	0.12
0.52	0.47	0.20	0.62
0.47	0.36	0.29	0.43
0.61	0.39	-0.14	0.26
0.00	0.22	0.18	0.50
0.32	0.20	-0.35	0.44
0.53	0.21	0.31	0.20
0.50	0.15	0.16	0.42
0.46	0.10	0.04	0.43
0.34	0.02	-0.25	0.40

Are there differences among the mean task scores for the four groups? Use = 0.05.

Follow the steps in solving the problem, namely:

1. Hypothesis ex. H0: = 9.0 H1: 9.0 2. Level of significance ex. = 0.01 3. Test Statistic ex. z = x - 0 / / n 4. Critical Region ex. graph and /2 = +-0.025 5. Computation ex. compute using formula 6. Decision ex. accept H0 since the computed z-value falls in the region of acceptance. 7. Conclusion ex. there is no reason to believe the ...