QUESTION 7 For a distribution with a standard deviation of 20, find z-scores that correspond to a) One-half of a standard deviation below the mean b) 5 points above the mean c) Three standard deviations above the mean d) 22 points below the mean QUESTION 8 At a high school, the teachers were concerned about grade inflation, and suggested that the school should issue standardized grades (or z-scores), in addition to the regular grades. Jack was in four classes, each with 20 students. Jack's score, the class mean, and the class standard deviation are given below. Compute his standardized grade in each class. If we judged by standardized grades, where did he do the best? Where did he do the worst? Subject Jack's score mean Std dev. Maths 3.8 3.75 0.15 Physics 3.6 3.25 0.6 Biology 3.2 0.38 Geography 2.9 0.75