以数据统计为主题的英语作文
以数据统计为主题的英语作文
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 government units (states and statistics come from the same latin root status) and a gentlemanly gambling father who relied on mathematics to increa his skill at playing the odds in games of chance.
the influence of the mother on the offspring, statistics, is reprented by counting, measuring, describing, tabulating, ordering, and the taking of census-all of which led to modern descriptive statistics. from the influence of the father came modern inferential statistics, which is bad squarely on theories of probability.
describing collections involves tabulating, depicting and describing collections of data. the data may be quantitative such as measures of height, intelligence or grade level-----
-variables that are characterized by an underlying continuum---or the data may reprent qualitative variables, such as x, college major or personality type.
large mass of data must generally undergo a process of summarization or reduction before they are comprehensible. descriptive statistics is a tool for describing or summarizing or reducing to comprehensible form the properties of an otherwi unwieldy mass of data.
inferential statistics is a formalized body of methods for solving another class of problems that prent great of problems characteristically involves attempts to make predictions using a sample of obrvations. 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 inefficient to question each child: the proportion for the sample of as few as 100 children. thus , the purpo of inferential statistics is to predict or estimate cha
racteristics of a population from a knowledge of the characteristics of only a sample of the population.
