Researchers investigated whether drinking alcohol the evening before a test hurts the test-taking performance of college students. They recruited a random sample of 193 college students who each participated in the study twice. In random order, one evening they were given regular beer and another evening they were given non-alcoholic beer (placebo). Here is a summary of their scores on a verbal test taken the morning after each evening of drinking: Beer Placebo Difference Mean 495.39 497.62 -2.23 Standard 97.79 86.43 61.02 Deviation Question 2: What is the test statistics for this test? O Xd -2.23 Z = = -0.008320302 61.02- na V193 O Xd -2.23 = -0.008320302 61.02- Vid V193 O Xd -2.23 2 = Od =-0.5077049 61.02 vna V193 O -2.23 1= Sad = 61.02 =-0.5077049 na V193