8 students were asked to rate how helpful they felt review classes were before & after they took the classes. The instructors felt their classes would be more helpful to students. Before After 5 6 6 6 9 6 5 10 (Use for 19-21) 19. What is the critical value at the .05 level of significance? 1pt 20. What is the test statistic? 4 pts 21. At an 0.05 level of significance, can we conclude that the review classes were helpful? 1pt