答案和详解如下： 1、What is the main difference between descriptive statistics and inferential statistics? A) Descriptive statistics are used to make forecasts about the likelihood of upcoming events while inferential statistics are used to summarize any data set. B) Descriptive statistics are calculations based on small samples while inferential statistics are calculations based on large samples. C) Descriptive statistics are used to summarize data while inferential statistics are used to obtain precise information about a large data set. D) Descriptive statistics are used to summarize a large data set while inferential statistics involves procedures used to make forecasts or judgments about a large data set by examining a smaller sample. The correct answer was D) Descriptive statistics are used to summarize a large data set while inferential statistics are based on procedures used to make forecasts or judgments about a large data set by examining a smaller set of data. 2、Which one of the following alternatives best describes the primary use of descriptive statistics? A) They are used to summarize important characteristics of large data sets. B) They are used to obtain data about the characteristics of any data set that can be used to assess the likelihood of the occurrence of future events. C) They are used to make forecasts based on large data sets. D) They are used to arrive at estimates regarding a large set of data regarding the statistical characteristics of a smaller sample. The correct answer was A) Descriptive statistics are used mainly to summarize important characteristics of large data sets. 3、Which one of the following alternatives best describes the primary use of inferential statistics? A) They are used to approximate the characteristics of any data set. B) They are used to make forecasts based on large data sets. C) They are used to summarize the important characteristics of a large data set based on statistical characteristics of a smaller sample. D) They are used to make forecasts, estimates or judgments about a large set of data based on statistical characteristics of a smaller sample. The correct answer was D) Inferential statistics are used mainly to make forecasts, estimates or judgements about a large set of data based on statistical characteristics of a smaller set of data. 4、A summary measure that is computed to describe a population characteristic from a sample is called a: A) census. B) summary. C) parameter. D) statistic. D) The correct answer was When sampling from a portion of the population, you compute a statistic to make inferences about the population. 5、Which of the following statements about statistical concepts is FALSE? A) A frequency distribution is a tabular display of data summarized into a relatively small number of intervals. B) An interval is a set of return values within which an observation falls. C) A parameter is any descriptive measure of a population characteristic. D) A sample contains all members of a specified group, but a population contains only a subset. The correct answer was D) A population is defined as all members of a specified group, but a sample is a subset of a population. 6、Which of the following statements regarding the terms population and sample is least accurate? A) Observing all members of a population can be expensive or time consuming. B) A sample includes all members of a specified group. C) A sample's characteristics are attributed to the population as a whole. D) A descriptive measure of a sample is called a statistic. The correct answer was B) A population includes all members of a specified group. A sample is a portion, or subset of the population of interest. | 
发表于 2008-4-8 17:15
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