Consider the following graphical display that appeared in the New York Times: Based on the data summarized in the graph, we can see that students who have a high school GPA or 3.5 or higher and a combined SAT score of over 1200 have an 89% graduation rate when they attend a “most selective” college, but only a 59% graduation rate when they attend a “least selective” college. Give an example of a potential confounding variable that might explain why the following statement is not reasonable: If all the students that have a GPA of 3.5 or higher and a combined SAT score of 1200 or higher and that were admitted to a “least selective” college were moved to a “most selective” college, the graduation rate for these students would be approximately 89%.