Question 2)

Researchers implemented an intervention designed to reduce adolescent aggressive behavior problems. The intervention was given to N = 40 adolescents when they were 10 and then their aggressive behavior problems were measured 6 years later when they turned 16. The overall average at age 16 was 1.18 aggressive behaviors in the past year (SD or s = .43).

A) Hand-calculate the standard error for the mean. Add your hand written notes by taking a picture of your notes and inserting the image into this document.

B) Hand-calculate the one-sample t-statistic for this mean. Add your hand written notes by taking a picture of your notes and inserting the image into this document.

C) What are the degrees of freedom for this t-statistic?

D) Based on this t-statistic, can you conclude that the mean is significantly greater than zero? Explain your answer.