Question

1. 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 a 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 u= 50 and a standard deviation of o= 15. The sample of group participation adolescents had an average of M=53.8. a. Does this sample provide enough evidence to conclude that self-esteem scores for these adolescents are significantly different from those of general population? Use a two-tailed test with a=.05. Write your results in APA style. b. Compute Cohen's d to measure the size of the difference.

APA style please

Answer 1

M = 50 6 = 15 laSolution;- we are given n=100 Sample mean (M)= 53.8 Ho: M= 50 : Self-esteem Scores for these adolescents are not significantly different from those of general population. His MĖ 50 ; (two-tailed) Self-esteem Scores for these adolescents are significantly different from those of general population. Test statistic. Under Ho the test statistic is : Za M-M

Date IZ = for these addescente are significantly different 3.8 Zs 53.8 - 50 15 /100 15/10 3,8 2.5333 1.5 Z= 2.5333 Critical value of Z at 5% level of Significance for two-tailed test is 1.96 Since Calculated z > Critical Z 2.5333 > 1.96 So, we reject the null hybothesis (HO) at 5% level of significance and conclude that (M+50 Self-esteem scores for these adolescente are significantly different from those of general population we can say that the sample provide enough evidence to conclude that self-esteem Scores from those of generat population! 9

(b) Cohen's d to measure the size of the difference d = (Msample - Mpopulation d = 53.8 - 50 15 d = 0.2533 3.8 15 d 0,2533 Small effect means difference is 0:2 Standard deviation.