Fig 1 9 An iron factory manufactures eight steel bars and th

Fig. 1 9. An iron factory manufactures eight steel bars and their length data is as following: 5.6, 5.4, 5.3, 5.5, 5.2, 5.2, 5.3,5.6 (meter) (a) The target length of the steel bars is 5.4 meter. Try to determine whether these goods pass the test or not? (Describe your reason briefly) (5%) (b) If the length of the steel bars in this factory is normally distributed, we want the yield rate of these goods is up to 99.73%. Please calculate the tolerant range of the length. (2%) 10. There is an exam and the grades of the students are normally distribution. We know the average is 66.45 and standard deviation is 6.45. (a) There are 50 students majoring this course. If one has to get above 60 scores to pass this course, how many students would be failed? (3%) (b) If the teacher wants to fail 0.775% of all students, what\'s the minimum score should you get to pass the course?

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