The accompanying summary statistics for a measure of social marginality for samples of youths, young adults. adults, and
seniors appeared in the paper "perceived causes of loneliness in adulthood" [journal of social behavior and personality
[2000]: 67—84). the social marginality score measured actual and perceived social rejection, with higher scores indicating
greater social rejection. for purposes of this exercise, assume that it is reasonable to regard the four samples as
representative of the u. s. population in the corresponding age groups and that the distributions of social marginality
scores for these four groups are approximately normal with the same standard deviation. is there evidence that the mean
social marginality score is not the same for all four age groups? test the relevant hypotheses using a a = .01
young
age group youth admits adults seniors
sample size '06 255 314 36
e 2.00 3.40 3.07 2.84
s ls6 l68 [.66 l.89