Researchers at the City University of New York (CUNY) identified 717 students who originally placed into an Elementary Algebra course. The students agreed to participate in a study related to the role of corequisite remediation and study skills. In this study, the 717 students were randomly assigned to one of three courses:
Course 1: traditional Elementary Algebra, 

Course 2: Elementary Algebra with workshops designed to improve study skills, or
Course 3: Elementary Statistics with corequisite remediation and study skills workshops. The courses were all taught at CUNY for one semester. At the end of the semester, the instructors for the course reported whether the student passed the class, or not. The data below show the outcome of the study.