The class mean at the end of the semester is 73 with a standard deviation of 12. He decides that the top 12% of the class should get an A, the next 24% should get a B, the next 36% a C, the next 18% a D and the last 10% of the class will get an F. What are the cutoffs for the grades? 8.6 Applications of the Normal Distribution Example – a machine that fills quart milk cartons is set to average 32.2 oz with a standard deviation of 1.2 oz. What is the probability that a filled carton will have more than 32 oz? If the store receives 500 quart milk cartons, how many will have more than 32 ounces? The mean height for 18 year old girls is 64.5 inches (50th percentile), with a standard deviation of 1.875 inches. These heights closely approximate the normal distribution. (this data is old) a) What is the probability that a woman is shorter than 5″ 3″?