Childhood participation in sports, cultural groups, and youth groups appears to be related to improved self-esteem for adolescents. (mcgee, williams, howden-chapman, martin & kawachi, 2006). in representative study, a sample of n = 100 adolescents with a history of group participation is given a standardized self-esteem questionnaire. for the general population of adolescents scores on this questionnaire form a normal distribution with a mean of ? = 50and a standard deviation of ? =15. the sample group-participation adolescents had an average of m=53.8.

a) does the sample provide enough evidence to conclude that self-esteem scores for those adolescents are significantly different from those of the general population? use the two tailed test with a=
0.05
b) comput cohens d to measure the size of the difference.
c) write a sentance describing the outcome of the hypothesis test and the measure of the effect size as it would appear in a research report.