The following five students were ranked in terms of when they completed an exam (1 = first to finish, 2 = second to finish, and so on) and were given an exam grade by the instructor. Test the null hypothesis of no relationship between grade (X) and length of time to complete the exam (Y) (that is, compute a rank-order correlation coefficient and indicated whether it is significant).
X Y
53………………………. 1
91………………………. 2
70………………………. 3
85………………………. 4
91………………………. 5