9 Worksheet 1 9.1 Empirical Rule (68-95-99.7) 1. The final scores in a large class on Principles of Statistics are normally distributed with mean score of 60 (u = 60) and standard deviation of 10 (o = 10). (a) Sketch the normal curve that represents the distribution of the final scores, and clearly indicate its mean () and standard deviation (o). (b) If the lowest passing score is 50, what proportion of the class is failing? (c) If the highest 80% of the class is to pass, give an estimation of the lowest passing score