An experimental psychologist at a Veterans Administration hospital obtained approval

from the Institutional Review Board to conduct a study of the efficacy of Pristiq for

treating depression. The experiment lasted 60 days, during which one group of depressed

patients was given placebos, one was given a low dose of Pristiq, and one was given a

high dose. At the end of the experiment, the patients were observed by two outside

psychologists, who rated several behaviors such as eye contact, posture, verbal output,

and activity for degree of depression. The ratings went into a composite score for each

patient, with high scores indicating depression. The means were as follows: placebo,

18.86; low dose, 10.34; and high dose, 16.21. An ANOVA summary table and two Tukey

HSD tests are shown in the accompanying table. Write conclusion using

the terms in the problem (not "The null hypothesis was rejected at the .05 level")

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