Descripitive statistics involves tabulating, depicting, and describing collections of data. These data may be either quantitative, such as measures of height, intelligence, or grand 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 reduction before they are comprehensible. Descriptive statistics is a tool for describing or summarizing or reducing to comprehensible from 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 prediction using a sample of observations. For example, a school superintendent wishes
to determine of 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 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.
36.With what is the passage mainly concerned?
A.The drawbacks of descriptive and inferential statistics.
B.Applications of inferential statistics.
C.The development and use of statistics.
D.How to use descriptive statistics.
37.Why does the author mention the “mother” and “father” in the first
paragraph?
A.To point out that parents can teach their children statistics.
B.To introduce inferential statistics.
C.To explain that there are different kinds of variables.
D.To present the background of statistics in a humorous and understandable way.
38.Which of the following is NOT given as an example of qualitative variable?
A.Gender. B.Height.
C.College major. D.Type of personality.
39.Which of the following statements about descriptive statistics is best
supported by the passage?
A.It simplifies unwieldy masses of data.
B.It leads to increased variability.
C.It solves all numerical problems.
D.It changes qualitative variables to quantitative variables.
40.According to the passage which is the purpose of examining a sample of
a population?
A.To compare different groups.
B.To predict characteristics of the entire population.
C.To consider all the quantitative variables.
D.To tabulate collections of data.
Part Ⅲ Vocabulary and Structure (20 minutes)
Directions: There are 30 incomplete sentences in this part. For each sentence there are four choices marked A),B),C) and D). Choose the one answer that best completes the sentence. Then mark the corresponding letter on the answer sheet with a single line through the centre.
