Jack, a production manager, is trying to improve the efficiency of his assembly line. He knows that the machine set up correctly only 60% of the time. He also knows that if the mechine is set up correctly, it will produce good parts 80% of the time. But if set up incorrectly, it will produce good part only 20% of the time. a. What is the probability of producing good parts blacks starts the machine and produces one part before he begins the production run. He finds the firs part to be good. What is the revised probability that the machine was set up correctly? Supposed there were 4000 students took a test and the resulting scores were normally distributed. It is known as second quartile 02 of the population is 63.25 and the third quartile is 72.31. a. What is the average score of all students? b. What is the Standard Deviation of all students? c. What is the first quartile Q1? d. About how many students scored above 80