Perry Preschool and Graduation from High School
The Perry Preschool Project was created in the early 1960s by David Weik art in Ypsilanti, Michigan.
In this project, 123 African American children were randomly assigned to one of two groups: One group enrolled in the Perry Preschool, and the other group did not.
Follow-up studies were done for decades. One research question was whether attendance at preschool had an effect on high school graduation.
The table shows whether the students graduated from regular high school or not and includes both boys and girls (Schweinhart et al. 2005).
Find a 95% confidence interval for the difference in proportions, and interpret it.