Question

The ACME coping scale measures social coping behaviors. Nationally, the average score on the ACME scale for adolescent girls is 53 ( = 53), with a standard deviation of 11 (σ = 11). A psychologist developed a behavioral intervention program designed to increase social coping behaviors for adolescent girls. 36 girls participated in the program. Upon completion their average ACME score was 57 (M = 57). Using the α = .05 significance level, determine if the program led to increased coping behaviors.

Answer 1

Given:

= 53, n = 36, = 57, = 11, = 0.05

Hypothesis:

Ho: = 53

Ha: > 53

Test statistic:

Critical value:

Z = Z _0.05 = 1.64 .....................From standard Normal Table

Decision Rule:

Z > Z, Then Reject Ho at 5% level of significance.

Conclusion:

Since the observed value of the test statistic Z = 2.18, is larger than the critical value 1.64 at 5% level of significance, the data provide us evidence against the null hypothesis Ho and in favour of Ha. Hence Ha is accepted and conclude that the program led to increased coping behaviours.