Bullying behavior study. School bullying is a form of aggressive behavior that occurs when a student is exposed repeatedly to negative actions (e.g., name-calling, hitting, kicking, spreading slander) from another student. In order to study the effectiveness of an antibullying policy at Dutch elementary schools, a survey of over 2,000 elementary school children was conducted (Health Education Research, Feb. 2005). Each student was asked if he or she ever bullied another student. In a sample of 1,358 boys, 746 claimed they had never bullied another student. In a sample of 1,379 girls, 967 claimed they had never bullied another student.

a. Estimate the true proportion of Dutch boys who have never bullied another student.

b. Estimate the true proportion of Dutch girls who have never bullied another student.

c. Estimate the difference in the proportions with a 90%

confidence interval.

d. Make a statement about how likely the interval you used in part c contains the true difference in proportions.

e. Which group is more likely to bully another student, Dutch boys or Dutch girls?