In a study of SAT scores, a researcher believes that students will score significantly higher on their second attempt at the exam. To test this claim, 9 students were randomly selected. Their scores on the first and second attempts at the SAT exam are shown below: Student | A B C D E F G H I First SAT score | 480 510 530 540 550 560 600 620 660 Second SAT score | 490 520 550 530 580 580 610 640 690 What is the test statistic for this test