Dr. Gomez conducted an experiment on studying alone vs. in a group. Twelve participants were randomly assigned to study a short chapter of a statistics test with either a group of students or alone. Twenty-four hours after the study session ended, the participants took an examination on the information in the chapter and the number of correct answers was recorded. Data from the experiment and the mean (X-bar) and standard deviation (SD) for each group are given below. Compute the difference between the means as the Alone minus Group Study Method.
Study Method
Alone (A) Group (G) X-barA = 445/6 = 74.167 SDA = 7.305
74 55
67 67 X-barG = 343/6 = 57.167 SDG= 6.646
87 55
77 47
68 59
72 60
What is the observed value of the test statistic?
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