If a Research Article Reports That "The Mean Performance Scores

Multiple Choice

If a research article reports that "The mean performance scores for the Normal Sleep,Reduced Sleep,and No Sleep groups were 18.0,16.6,and 15.6,respectively,F (2,36) = 2.95,p < .05," the most accurate conclusion is that

A) people who get no sleep perform significantly worse than people who sleep a reduced amount.
B) people who get no sleep perform significantly better than people who sleep a normal amount.
C) the three groups do not all come from populations with the same mean,although it is not clear which population means are different.
D) conclusions about the relationship between amount of sleep and performance cannot be drawn from these results.