Giải tích 1 - Chapter 1: Data and statistics

Chapter 1 DATA AND STATISTICS MBA Nguyen Tien Dung School of Economics and Management Website: https://sites.google.com/site/nguyentiendungbkhn Email: dung.nguyentien3@hust.edu.vn Main Contents 1.1 Applications in Business and Economics 1.2 Data 1.3 Data Sources 1.4 Descriptive Statistics 1.5 Statistical Inference 1.6 Computer and Statistical Analysis 1.7 Data Mining 1.8 Ethical Guidelines for Statistical Practice © Nguyễn Tiến Dũng 2Applied Statistics for Business 1.1 Applications in Business and Economics ● Statistics is essential for all other sciences ● Statistics about data ● All sciences need to get, to analyse and to present data and results ● For a business ● R&D (Research & Development) ● Marketing ● Production ● Quality ● Human Resources ● Accounting ● Finance ● Information ● For economics ● Policies for developing cities, districts, provinces and nations. © Nguyễn Tiến Dũng 3Applied Statistics for Business 1.2 Data ● Elements: the entities on which data are collected. ● Variables: a characteristic of interest for the elements. ● Observations: the number of observations or the size of a sample © Nguyễn Tiến Dũng 4Applied Statistics for Business ● 60 elements, 60 observations ● 5 variables © Nguyễn Tiến Dũng 5Applied Statistics for Business Features of Data ● Scale of Measurement ● Nominal ● Ordinal ● Interval ● Ratio ● Categorical and Quantitative Data ● Categorical: nominal, ordinal data ● Quantitative Data: interval, ratio data ● Cross-sectional and Time-series data © Nguyễn Tiến Dũng 6Applied Statistics for Business Nominal Scale and Data ● Distinguish between items, do not rank them. ● Are you 1. Male? 2. Female? ● What is your marital status? ● 1. Single 2. Married 3. Divorced © Nguyễn Tiến Dũng 7Applied Statistics for Business Ordinal Scale and Data ● Ranking items, do not know the distance between them. ● Are you ● 1. A junior student? ● 2. A senior student? ● What is your average monthly income? ● 1. Below USD 200 ● 2. From USD 201 – 400 ● 3. From USD 401 – 600 ● 4. From USD 601 – 800 ● 5. From USD 801 – 1000 ● 6. Above USD 1000 © Nguyễn Tiến Dũng 8Applied Statistics for Business Interval Scale and Data ● Measures the distance between items, but does not have an absolute zero (anchor) point. ● Temperature scale: Celcius, Farenheit degree scales ● How do you feel about the Statistics course? ● Very easy 1 2 3 4 5 Very difficult ● Very unuseful 1 2 3 4 5 Very useful © Nguyễn Tiến Dũng 9Applied Statistics for Business Ratio Scale and Data ● Interval scale + an absolute and meaningful zero point. ● Time, distance scale: hour, minute, centimetre © Nguyễn Tiến Dũng 10Applied Statistics for Business Distribution of University Entry National Exam Marks (2013) © Nguyễn Tiến Dũng 11Applied Statistics for Business Weather Statistics © Nguyễn Tiến Dũng 12Applied Statistics for Business © Nguyễn Tiến Dũng 13 Source: accessed 16 Aug 2014 Applied Statistics for Business 1.3 Data Sources ● Existing sources (secondary data) © Nguyễn Tiến Dũng 14Applied Statistics for Business © Nguyễn Tiến Dũng 15Applied Statistics for Business General Statistical Office in Vietnam: www.gso.gov.vn © Nguyễn Tiến Dũng 16Applied Statistics for Business © Nguyễn Tiến Dũng 17Applied Statistics for Business © Nguyễn Tiến Dũng 18Applied Statistics for Business Statistical Studies (primary data) ● Observational studies ● Descriptive research ● Including: ● Observations ● Diaries ● In-depth interviews ● Group discussions ● Surveys ● Experimental studies ● Causal research ● Including ● Experiments in a simulated condition ● Experiments in a real condition © Nguyễn Tiến Dũng 19Applied Statistics for Business Survey Questionnaires © Nguyễn Tiến Dũng 20Applied Statistics for Business Data Acquisition Error Data Acquisition Errors Sampling errors Non- sampling errors © Nguyễn Tiến Dũng 21 Due to sampling activities Due to other factors Applied Statistics for Business 1.4 Descriptive Statistics ● Describe things ● Frequency Tables ● Charts © Nguyễn Tiến Dũng 22Applied Statistics for Business © Nguyễn Tiến Dũng 23Applied Statistics for Business 1.5 Statistical Inference ● Collect data on a sample ● To infer conclusions to a population © Nguyễn Tiến Dũng 24Applied Statistics for Business © Nguyễn Tiến Dũng 25Applied Statistics for Business © Nguyễn Tiến Dũng 26Applied Statistics for Business 1.6 Computers and Statistical Analysis in Excel ● Note: Change “Region” to the English (UK) format ● Install Data Analysis Tool ● Add-ins: ● Analysis Toolpak ● Analysis Toolpak VBA ● MegaStat © Nguyễn Tiến Dũng 27Applied Statistics for Business 1.7 Data Mining ● Data Warehouse ● Data warehousing: the process of capturing, storing, and maintaining the data. ● Data mining ● Developing useful decision-making information from large data bases. ● Automated and predictive ● Techniques: multiple regression, logistic regression, correlation, modelling © Nguyễn Tiến Dũng 28Applied Statistics for Business 1.8 Ethical Guidelines for Statistical Practice ● "Lies, damned lies, and statistics“ ● A phrase describing the persuasive power of numbers, particularly the use of statistics to bolster weak arguments. ● It is also sometimes colloquially used to doubt statistics used to prove an opponent's point. © Nguyễn Tiến Dũng 29Applied Statistics for Business Homework ● 2, 3 ● 4, 13, 14, 15, 24, ● 25 (Shadow02) © Nguyễn Tiến Dũng 30Applied Statistics for Business