Some Critical Values that could be Useful: to.025,19 = 2.093, fo. 121,7,12 = 2.12, Xo.05,2 = 5.991, Xo.025.1 = 7.378, to.01,33 = 2.445 Problems: 2. (15 pt) In a study, data were collected to determine whether or not the proportion of defectives produced was the same for works on the day, evening, and night shifts. Day Evening Night Defectives 45 55 70 Nondefectives 905 890 870 Test if the proportion of defectives is the same for all three shifts using a = 0.05