1. Trying to determine the best cut-off value for determining a master in bowling, you look at professionals' scores and at the scores for students in a beginning bowling class. Professionals 220 180 140 190220212 170 165 145245 Students 101 110|80 155 189 177 145 103|89212 a. Using cut-off scores of 125, 150 and 175, what is the best value for P? b. What is the value of the best cut-off if you take out the effects due to chance