Introduction to the Course • Teaching staff: Assoc.Prof. Tran Thi Bich Statistics Faculty Email: bichtt@neu.edu.vn • Lectures: as indicated • Tutorials: 30 minutes - 1 hour, from lecture 2 to 7 • Materials: - Gerald Keller (2011).Statistics for Management and Economics (9th Edition). - SPSS Statistics: Guide to Data Analysis STATISTICS IN BUSINESS & ECONOMICS Advanced Educational Program 2 1 2 Goals Topics will be covered Develop an understanding of a variety of quantitative and statistical techniques that can be applied to a wide range of business situations. • Data Presentation: Tables and Charts • Data Presentation: Central Tendency and Dispersion • Probability and Random variables • Sampling distribution and Estimation • Hypothesis Testing • Regression Analysis Use statistical software applications to perform essential and practical data analysis for business organizations. Demonstrate the ability to prepare and analyze a variety of data sets for specific purposes. Determine which statistical techniques are best suited to which organizational problems. 3 3 4 4 How to achieve 10% of participation? Assessment • Contribution in class and tutorials. • Before a new lecture, you need to work on the topic’s main points that are assigned. • You may also ask question. • Compliance with the class rules: • Participation: 10% • Mid-term exams: 40% – Two midterm exams, each accounts for 20% • Final exams: 50% • Further details (including date of exams and deadline of assignments) given during the course. – Come prepared – read the readings assigned. – Turn off cell phones during classes. – Use laptop only when being indicated – Do not engage in individual discussions 5 5 6 6 1 Mid-term exams: 40% • One group mid-term exam: How to do the group mid-term exam • You select an article which is suited to the topic. • Your work includes two parts: o Part 1: summarise the article 20% Topic for group mid-term exams: - Descriptive statistics - Probability - Sampling distribution and Estimation - Hypothesis testing • Individual in-class mid-term exam: - What is the issue of interest? - Why do you care about the technique as the organisation manager? - You need to find two additional sources and cite those references. - I am interested in your opinion which you need a few different viewpoints to develop. 20% o Part 2: Data analysis to a specific organisational problem. 7 7 8 8 Timetable for group mid-term exam Hints for success • You are assigned the topic on Monday. • Attend lectures and tutorials, supplement given materials with your own comments and notes. • Work carefully on the tutorials – doing them is how you will understand and learn • Time spent trying questions is well spent • Constantly REFER to notes • Use resources provided • You need to send your work to the class by the following Thursday. • Other students have 3-3.5 days to read your work and prepare for their discussion. • Each group has maximum 10’ for the presentation, which is followed by 10’ individual discussions. 9 9 10 10 Outline Lecture 1 • Introduction to statistics • Basic concepts: variables and data • Getting acquainted with SPSS Introduction to Statistics and SPSS Reading materials: Chap 1, 2 (Keller) 12 11 12 2 What is statistics? 13 13 14 14 What is statistics? • This is not a matter of ordering soup! Statistics involves matters of life and death… – If the probability of getting accident of an airplane is 1/10,000, what is your chance of survival when you are on board? – How do you know? • To accomplish the above feat, Statisticians rely on three related disciplines: – Data analysis – Probability – Statistical inference 16 15 15 16 The question is … So… • How to get useful information from data to make a correct decision? It’s not easy! • Statistics is all about collecting, organising and interpreting data • Statistics is a way to get information from data and make decisions under uncertainty • Statistical analysis of data uses statistical modelling and probability: our main focus is on data and techniques for analysing data 17 17 18 18 3 Why is statistics important? Why is statistics important? • • • • • • Financial management (capital budgeting) Marketing management (pricing) Marketing research (consumer behaviour) Operations management (inventory) Accounting (forecasting sales) Human resources management (performance appraisal) • Information systems • Economics (summarising, predicting) 19 19 20 20 Types of statistics Questions for Data Analysis • Descriptive statistics: • In the descriptive statistics: Collecting, organising, summarising, and presenting data E.g: graphical techniques; numerical techniques What is the general pattern of the studied variable Applied for population or sample • In the exploratory statistics: • Exploratory statistics: What is the relationship amongst variables? Applied for population or sample Identifying relationships/associations E.g: factor analysis • In the inferential statistics: • Inferential statistics: What can we infer for the population based on sample results Applied for population Estimating, predicting, and making decisions about population based on sample data E.g: estimation; hypothesis testing 21 21 22 22 Basic concepts: variables and data Types of data • A variable is some characteristics of population or sample items Data Eg: • Height of students • Occupation of students upon graduation Qualitative • Data are the observed values of a variable Eg: • Height of 10 students: 1.6, 1.7, 1.55, 1.59, 1.5, 1.58, 1.64, 1.67, 1.58, 1.55 • Occupation of 5 students: teller, accountant, IT, marketing manager, teacher Nominal Discrete Continuous 24 23 23 Ordinal Quantitative (also called Interval) 24 4 Quantitative data Qualitative data (Categorical data) • Quantitative data are real number (can be measured) • Qualitative is the kind of data that cannot be measured (quantified) Eg: • Marital status: single, married, divorced, and widowed • Study performance of students: poor, fair, good, very good, excellent • Mid-term test marks of 10 students: 7, 8, 10, 5, 5, 6, 8, 9, 9, 7 • Weights of postal packages • Monthly salary • More classification: qualitative data can be classified as Nominal and Ordinal data Nominal data: cannot be quantified with any meaningful unit • More classification: quantitative data can be classified as interval and ratio data – Interval data: it includes all characteristics of ordinal data but the interval b/w values is meaningful and has no meaningful interpretation of zero on the scale Eg: - Marital status: single, married, divorced, and widowed Ordinal data: a sort of nominal data but their values are in order • Temperature: 10oC, 20oC, 40oC – Ratio data: data is based on a scale with a known unit of measurement and a meaningful interpretation of zero on the scale Eg: - Study performance of students: poor, fair, good, very good, excellent - Opinions of consumers: strongly disagree, somewhat disagree, neither disagree nor agree, agree, strongly agree • Weights of postal packages 25 25 26 26 Activity 1 More on quantitative data • Quantitative data can be divided into two types: discrete or continuous • For each of the following examples of data, determine the type: – Discrete data: take only integer value Eg: i. The number of miles joggers run per week • Number of children in family ii.The starting salaries of graduates of advanced program – Continuous data: can take any value Eg: iii.The months in which a firm’s employees choose to take their vacations • Monthly salary iv.The occupation of graduates of Advanced Program v. Teachers’ ranking 27 27 28 28 Sources of secondary data Data sources • Internet research • Based on the method of collecting information, data can be classified as Primary and Secondary • Search through Vietcombank website (www.vietcombank.com.vn) to know the exchange rate • Search through Google to gather information about the performance of private firms in Vietnam since ‘Doi moi’ – Primary data: collected by the organisation itself for the particular purpose • Government data and official publications • The General Statistics Office (GSO) of Vietnam provides all socioeconomic information (www.gso.gov.vn) • Data from surveys carried out by GSO and other organisations • The Ministry of Finance (www.mof.gov.vn) provides information on budget statement Eg: you need to know the consumer’s behaviour of Techcombank, then collect this information yourself – Secondary data: collected by other organisations for other purposes • Internal and by-product data: data collected from different departments in an organisation and used all together Eg: the Vietnam household living standards survey in 2010 • Data from Sale Department, Human resource Department => decision making 29 29 30 30 5 Population • Population is a set of all items or people that share some common characteristics A census is obtained by collecting information about every member of a population Basic concepts: population and sample - Collect the height of Vietnamese citizens - Verify the quality of all products that are produced by factory X • Parameter: a descriptive measure of a population ( , 2 ) 31 31 32 32 Sample Reasons to take sample (1) • A sample is a smaller group of the population. A sample survey is obtained by collecting information of some members of the population - Collect the height of 1,000 Vietnamese citizens • A census can give accurate data but population is so large - Verify the quality of a proportion of products that are produced by factory X • Statistics: a descriptive measure of a sample (x, s2 ) • Sampling: taking a sample from the population Collecting information from the entire population is time-consuming, expensive, and sometimes impossible. 33 33 34 34 Reasons to take sample (2) Important requirements • If we are willing to accept less than 100% accuracy, we collect information from a sample, calculate its statistics and use statistical inference to infer values of parameters of the population A sample must be representative for the population. That means the profile of the sample is the same as that of the population => apply sampling techniques • We can do this because: a certain sample size ensures that results from the sample are as accurate as those of the population The sample size is large enough • And benefits of sample: sample allows to investigate more detailed information 36 35 35 36 6 Moving from population to sample You need a sampling frame Population Sampling frame (a list of all items of the population) Sample 37 37 38 38 The second requirements Getting acquainted with SPSS The sample size is large enough • Import the file ‘assignment 1 data set.xls’ into SPSS and get familiar with SPSS. This question will be answered in lecture 7 39 39 40 40 7