For a class of 100 students, the teacher takes the 10 students who performed poorest on the midterm exam and enrolls them in a special tutoring program. Both the midterm and final have a class mean of 70 with standard deviation 10, and the correlation is 0.50 between the two exam scores. The mean for the specially tutored students increases from 50 on the midterm to 60 on the final. Can we conclude that the tutoring program was successful? Explain, identifying the response and explanatory variables and the role of regression toward the mean.