《Business statistic》复习参考(第一章至第八章).docx

《Business Statistic》 中国人民大学出版社 英文版 第五版 chapter1~8复习参考 Part1名词解释 Statistics is a method of extracting useful information from a set of numerical data in order to make a more effective and informed decision. Descriptive Statistics：These are statistical methods of organizing, summarizing and presenting numerical data in convenient forms such as graphs, charts and tables. Inferential statistics is defined as statistical methods used for drawing conclusions about a population based on samples. Primary data is obtained first hand. Secondary data already exists or has been previously collected such as company accounts, or sales figures. Mean: The arithmetic average and the most common measure ofaaaaaaa central tendency. ①All values are included in computing the mean.②A set of data has a unique mean ③The mean is affected by unusually large or small data points (outliers / extreme values). Mode: The most frequent data, or data corresponding to the highest frequency. ①Mode is not affected by extreme values. ②There may not be a mode. ③There may be several modes. ④Used for either numerical or categorical data. Median is the value that splits a ranked set of data into two equal parts. ①Median is not affected by extremely large or small values and is therefore a valuable measure of central tendency when such values occur. Standard Deviation: ①A measure of the variation of data from the mean. ②The most commonly used measure of variation. ③Represented by the symbol ‘s’. ④Shows how the data is distributed around the mean. Probability is the chance of an occurrence of an event. ①Probability of an event always lies between 0 and 1. ②The sum of the probabilities of every possible outcome or event is 1. ③The probability of the complement A’ is given by 1-P(A). Properties of Normal distribution：①Continuous random variable. ②‘Bell-shaped’ symmetrical. ③Mean, median, mode are equal ④Area under the curve is 1. The Central Limited Theorem：①If the population followed normal distribution, t