课程名称：统计学 课程性质：整开 课程范围：ch1~6 开课教师：陈心苹 开课学院： 开课系级： 考试日期(年月日)：98/11/19 考试时限(Mins)：2hrs 试题本文： 1.Recent information published by the U.S Environmental Protection Agency indicates that Honda is the manufacturer of four of the top nine vehicles in terms of fuel economy.What is the likelihood that in the sample of three at least one Honda is included? (10%) 2.A study of business faculty at state supported institutions in Ohio revealed that the arithmetic mean salary for nine months is $52,000 and a standard deviation of $3000. The study also showed that the faculty had been employed an average (arithmetic mean) of 15 years with a stardard deviation of 4 years. How does the relative dispersion in the distribution of salaries compare with that of the lengths of service? (10%) 3.Auto Insurance classifies drivers as good, median, or poor risk. Drivers who apply to them for insurance fall into these three groups in the proportions 30 percent, 50 percent, and 20 percent, respectively. The probability a "good" driver will have an accident is .01, the probability a "median" risk driver will have an accident is .03, and the probability a "poor" driver will have an acciden is .10. The company sells Mr.Chen an insurance policy and he has an accident. What is the probability Mr.Chen is a "good" driver? (10%) 4.A manufacturer of window frames knows from long experience that 5 percent of the production will hace some type of minor defect that will require an adjustment. What is the probability that in a sample of 20 window frames at least one will need adjustment? (10%) 5.The data as follow: 29 32 37 34 38 22 33 57 21 65 35 52 46 35 54 26 55 59 22 30 38 39 31 20 69 19 58 42 50 51 (a) Construct a stem-and-leaf display for the above data. (5%) (b) From the above stem-and-leaf display, find the minimum value, the 1st quartile, the median, the 3rd quartile, and the maximum value. List and interpret the interquartile range. (10%) 6.Suppose the National Hurricane Center forecasts that hurricanes will hit the strike area with a .95 probability. What is the probability at least one of 10 hurricanes reaches land outside the strike area? (10%) 7.For the daily lottery gamein Illinois, participants select three numbers between 0 and 9. A number cannot be selected more than once, so a winning ticket could be, say, 307 but not 337. Purchasing one ticket allows you to select one set of numbers. The winning nimbers are announced on TV each night. If you purchase a ticket for the game tonight, what is the likelihood you will win? (10%) 8.De, Richmond, a psychologist, is studying the daytime television viewing habits of college students. He believes 40 percent of college students watch soap operas during the afternoon. To further investigate, he select a sample of 10. (a) Develop a probability distribution for the number of students in the sample who watch soap operas. (10%) (b) Find the mean and stardard deviantion of this distribution. (5%) (c) What is the probability of finding exactly three watch soap operas. (5%) (d) What is the probability less than half of the students selected watch soap operas? (5%) 注:我个人觉得觉得第6题的英文语法有点怪怪的 --

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