urgent help plese

The following table contains the first exam score and the last exam score for a random sample of 14 students in a certain math class. First Exam (%) 86 90 81 84 83 87 77 85 75 82 76 89 80 79 Last Exam (%) 80 81 71 74 74 90 75 83 69 73 68 79 71 78 Difference 6 9 10 10 9 -3 2 2 6 9 8 10 9 1 Send data to calculator At the 0.05 level of significance, can we conclude (by using a sign test) that there is a difference between the two exam scores in this class? Perform this hypothesis test by completing the parts below. (If necessary, consult a table with critical values for the sign test.) (a) Find the value of the test statistic. X 5 2 (b) Find the critical value. (c) Give the decision. (Choose one) (d) Can we conclude that there is a difference between the two exam scores in this class? O Yes O No