Passage Two Questions 26 to 30 are based on the following passage.
There were two widely divergent influences on the early development of statistical methods. Statistics had a mother who was dedicated to keeping orderly records of governmental units （state and statistics come from the same Latin root status） and a gentlemanly gambling father who relied on mathematics to increase his skill at playing the odds in games of chance. The influence of the mother on the offspring, statistics, is represented by counting, measuring, describing, tabulating, ordering, and the taking of censuses-all of which led to modern descriptive statistics. From the influence of the father came modern inferential statistics, which is based squarely on theories of probability.
Descriptive statistics involve tabulating, depicting, and describing collections of data. These data may be either quantitative, such as measures of height, intelligence, or grade level-variables that are characterized by an underlying continuum-or the data which represent qualitative variables, such as sex, college major, or personality type. Large masses of data must generally undergo a process of summarization or reduction before they . Descriptive statistics is a tool for describing or summarizing or reducing to comprehensibly form the properties of an otherwise unwieldy mass of data.
Inferential statistics is a formalized body of methods for solving another class of problems that present great difficulties for the unaided human mind. This general class of problems characteristically involves attempts to make predictions using a sample of observations. For example, a school superintendent wishes to determine the proportion of children in a large school system who come to school without breakfast, have been vaccinated for flu, or whatever. Having a little knowledge of statistics, the superintendent would know that it is inefficient to question each child; the proportion for the entire district could be estimated fairly accurately from a sample of as few as 100 children. Thus, the purpose of inferential statistics is to predict or estimate characteristics of a population from a knowledge of the characteristics of only a sample of the population.
26. What is the passage mainly concerned with? (A) Development and application of statistics. (B) Origin of descriptive statistics. (C) Limitations of inferential statistics. (D) Importance of statistics.
27. Describing and tabulating are associated with ______. (A) inferential statistics (B) descriptive statistics (C) theories of probability (D) inefficiency of counting
28. Which of the following statements is TRUE about descriptive statistics? (A) It combines quantitative variables and qualitative variables. (B) It can be used to deal with only quantitative variables. (C) It helps to summarize properties of a group of data. (D) It helps to make predictions using a sample of observations.
29. The word “unwieldy” （Line 6, Para. 2） is closest in meaning to ______. (A) difficult to collect (B) difficult to tackle (C) incomprehensive (D) uncontrollable
30. A sample of a population is often examined for the following purposes EXCEPT ______. (A) to make a more accurate prediction of trend (B) to improve efficiency and avoid unnecessary work (C) to save the trouble of approaching every member (D) to predict characteristics of the entire population
Passage Two 文章精要：本文以拟人化的手法介绍了两种基本统计方法的发展内容及应用。其中， 描述性统计法以整理数据为基础， 包括计算、 测量、 列表、 排序、 描述等， 既可统计数量也可统计质量； 而推理统计法则是先进行抽样分析， 进而总结， 得出整体性的统计结论。 26. A 主旨题。通观全文， 特别是文章的第一段可知， 文章主要讨论了统计学的发展与应用， 所以A正确。 27. B 细节题。由文章第二段可知， 描述和列表是描述性统计法的两种形式， 所以B正确。 28. C 细节题。文章第二段最后一句指出， 大量的数据群在易于被理解前必须经历一个总结或删减的过程， 以便把繁杂的数据群的特征描述或概括为可理解的形式， 所以C正确。描述性统计法统计的数据是关于数量和（或）质量的变量， 但并不是要合并这两种变量， 排除干扰项A。 29. B 由该句的comprehensibly form可知描述性统计处理后的数据的特点是“可理解的”， 再由接下来的otherwise可知， unwieldy与comprehensible意思相反， 故选B。注意incomprehensive （范围不广的）与incomprehensible（难理解的）的区别。 30. A 细节题。本题可采用排除法。结合文章最后两句可知， B（提高效率， 避免不必要的工作）是抽样调查的作用； C（省去找每个成员的麻烦）是抽样调查的优势； D（预测全体人群的特征）是抽样调查的目的； 而A（进行更准确的趋势预测）并没有提及， 所以选A。
. Descriptive statistics is a tool for describing or summarizing or reducing to comprehensibly form the properties of an otherwise unwieldy mass of data.
inefficient to question each child; the proportion for the entire district could be estimated fairly accurately from a sample of as few as 100 children. Thus, the purpose of inferential statistics is to predict or estimate characteristics of a population from a knowledge of the characteristics of only a sample of the population.
