An SAT prep course claims to improve the test score of students. The table below shows the scores for seven students the first two times they took...

An SAT prep course claims to improve the test score of students. The table below shows the scores for seven students the first two times they took the verbal SAT. Before taking the SAT for the second time, each student took a course to try to improve his or her verbal SAT scores. Do these results support the claim that the SAT prep course improves the students' verbal SAT scores?Let d=(verbal SAT scores prior to taking the prep course)−(verbal SAT scores after taking the prep course))