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育明考研考博培训中心官网:育明考研考博培训中心官网:www.yumingedu.comwww.yumingedu.com 北北京航空航天大学京航空航天大学 2010 年考博英语年考博英语试题试题 Part One Listening Comprehrnsion Part Two Reading Comprehernsion Passage 1 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 hu(wechat:13370142852)man 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. 21. Which of the following are counting and describing associated with? A . Descriptive statistics B . Unknown variables C . Qualitative changes D . Inferential statistics 22.Why does the author mention themotherandfatherin the first paragraph? A . To present the background of statistics in a humorous and understandable way. B . To point out that parents can teach their children statistics. C . To explain that there are different kinds of variables. D . To introduce inferential statistics. 23. Which of the following is true of descriptive statistics? A . It leads to increased variability. B . It solves all numerical problems. C . It simplifies unwieldy masses of data. 育明考研考博培训中心官网:育明考研考博培训中心官网:www.yumingedu.comwww.yumingedu.com D . It changes qualitative variables to quantitative variables. 24. What is the purpose of examining a sample of a population? A. To tabulate collections of data. B. To compare different groups. C. To consider all the quantitative variables. D. To predict characteristics of the entire population. 25. Which of the following might be the best title for this passage? A. How to use descriptive statistics? B. Applications of inferential statistics C. The development and use of statistics D. The drawbacks of descriptive and inferential statistics Passage 3 If a mother pushes her small son in a swing, giving only a light force each time he returns, eventually he will be swinging quite high. The child can do this for himself by using his legs to increase the motion, but both the mothers push and the childs leg movements must occur at the proper moment, or the extent of the swing will not increase. In physics, increasing the swing is increasing the amplitude; the length of the rope on the swing determines its natural oscillation period. This ability of an object to move periodically or to vibrate when stimulated by a force operating in its natural period is called resonance. Resonance is observed many times without consciously thinking about it; for example, one may find an annoying vibration or shimmy in an automobile, caused by a loose engine mount vibrating with increasing amplitude because of an out- of-round tire. The bulge on the tire slaps the pavement with each revolution; at the natural resonance point of the engine mount, it will begin to vibrate. Such vibrations can result in considerable damage if allowed to persist. Another destructive example of resonance is the shattering of a crystal goblet by the production of a musical tone at the natural resonant point of the goblet. The energy of the sound waves causes vibration in the glass; as its amplitude increases, the motion in the glass exceeds the elasticity of the goblet, and it s
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