2. 外语
  3. There were two widely divergent influences on the early development of statistical methods. Statistics had a mother who was dedi

There were two widely divergent influences on the early development of statistical methods. Statistics had a mother who was dedi

admin2010-01-26  84
问题     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 may 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.
A sample of a population is often examined for the following purposes except ______.
选项 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
答案A
解析 文章最后一段讲到抽样100个小孩来进行分析预测。A“进行更加准确的趋势预测”，抽样本身就不可能是为了更加“准确”，所以A错，应该选A。B“提高效率，避免不必要工作”，这正是抽样的作用；C“省去找每个成员的麻烦”，这也正是人口抽样的优势；D“预测全体人群的特征”，正是人口抽样的目的。所以选A。
转载请注明原文地址:https://www.kaotiyun.com/show/SDdK777K
0

大学英语六级

相关试题推荐
随机试题
最新回复(0)