In a respresentative study,a sample of n = 100 adolescents with a history of group participation is given a standardized self-esteem questionnaire. For the general po;ulation of adolescents, scores on this questionnaire form a normal distribution with a mean of u = 40 and a standard deviation of 12. The sample of group-participation adolescents had an average of M = 43.84.
A. Does this sample provide enough evidence to conclude that self-esteem scores for these adolescents are significantly different from those of the general population? Use a two-tailed test with standard error = .01
b. Compute Cohen's d to measure the size of the difference.
c. Write a sentence describing the outcome of the hypothesis test and the measure of effect size as it would appear in a research report.
2 answers
I thought college students knew the difference between the name of their school and the name of their school subject. (Sigh!)
For part a: Use the appropriate hypothesis test for your data.
For part b: Cohen's d is the difference between two means divided by a standard deviation.
Calculate Cohen's d (d) and the effect-size correlation (r) using the following formulas:
d = (M1 - M2) / s
r = d / √(d^2 + 4)
With your data:
d = (43.84 - 40) / 12 = 0.32
r = 0.32 / √(0.32^2 + 4) = 0.078
Check these formulas and calculations.
I'll let you take it from here.
For part b: Cohen's d is the difference between two means divided by a standard deviation.
Calculate Cohen's d (d) and the effect-size correlation (r) using the following formulas:
d = (M1 - M2) / s
r = d / √(d^2 + 4)
With your data:
d = (43.84 - 40) / 12 = 0.32
r = 0.32 / √(0.32^2 + 4) = 0.078
Check these formulas and calculations.
I'll let you take it from here.
1 answer