Researchers implemented an intervention designed to reduce adolescent delinquency. The intervention was given to N = 50 adolescents when they were 12 and then their delinquent behaviors were measured 4 years later when they turned 16. The overall average at age 16 was 1.26 delinquent behaviors in the past year (SD or s= .49). Where it says hand-calculate below, take a picture of your hand-written work and insert it into the exam.

1. Hand-calculate the standard error for the mean.

2. Hand-calculate the 95% Confidence Interval for the mean

3. Hand-calculate the one-sample t-statistic for this mean.

4. What are the degrees of freedom for this t-statistic?

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