2011概率统计期末考试试题(B卷).pdf

中山大学软件学院 20 1 0 级软件工程专业(2011 学年秋季学期) 《S E - 20 3 概率统计》期末试题(B 卷) ( 考试形式： 闭 卷 考试时间 : 2 小 时) 《中山大学授予学士学位工作细则》第六条 警 示 考 试 作 弊 不 授 予 学 士 学 位 方向： 姓名： ______ 学号： 1. (10) The amount of radiation received at a greenhouse plays an important role in determining the rate of photosynthesis. The accompanying observations on incoming solar radiation were 6.3 6.4 7.7 8.4 8.5 8.8 8.9 9.0 9.1 10.0 10.1 10.2 10.6 10.6 10.7 10.7 10.8 10.9 11.1 11.2 11.4 11.9 11.9 12.2 13.1 (1) Construct a stem-and-leaf display of the data (2) Compute the following values for these sample: mean x , median x , fourth spread f (f = upper fourth - lower fourth), s s and the standard deviation s. 2. (15) Six balls are to be randomly chosen from an urn containing 8 red, 10 green, and 12 blue balls. (1) What is the probability at least one red ball is chosen? (2) Given that no red balls are chosen, what is the conditional probability that there are exactly 2 green balls among the 6 chosen? 第- 1 -页 / 共4 页 3. (10) A customer visiting the suit department of a certain store will purchase a suit with probability 0.22, a shirt with probability 0.30, and a tie with probability 0.28. The customer will purchase both a suit and a shirt with probability 0.11, both a suit and a tie with probability 0.14, and both a shirt and a tie with probability 0.10. A customer will purchase all 3 items with probability 0.06. What is the probability that a customer purchases none of these items? 4. (10)