2019年英语六级阅读理解专项练习（十六）

　　Questions 31 to 35 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 involves 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 many represent qualitative variables, such as sex, college major, or personality type. Large masses of data must generally undergo a process of summarization 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 unnecessary and inefficiency 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.

　　31.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.

　　32.Describing and tabulating are associated with ____.

　　A) inferential statistics B) descriptive statistics

　　C) theories of probability D) inefficiency of counting

　　33.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.

　　34.The word "unwieldy" in the second paragraph is closest in meaning to ____.

　　A) difficult to collect B) difficult to tackle C) incomprehensive　D) uncontrollable

　　35.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 members

　　D) to predict characteristics of the entire population

　　【答案】31-35 A B C B A