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

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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.

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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

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● 60 elements, 60 observations ● 5 variables

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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

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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

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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

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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 ● ● Very unuseful

1 2 3 4 5 Very difficult 1 2 3 4 5 Very useful

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Ratio Scale and Data

● Interval scale + an absolute and meaningful zero

point.

● Time, distance scale: hour, minute, centimetre

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Distribution of University Entry National Exam Marks (2013)

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Weather Statistics

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Source: http://finance.vietstock.vn/, accessed 16 Aug 2014

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1.3 Data Sources

● Existing sources (secondary data)

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General Statistical Office in Vietnam: www.gso.gov.vn

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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

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Survey Questionnaires

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Data Acquisition Error

Data Acquisition Errors

Sampling errors

Non- sampling errors

Due to other factors

Due to sampling activities

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1.4 Descriptive Statistics

● Describe things

● Frequency

Tables ● Charts

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1.5 Statistical Inference

● Collect data on a

sample ● To infer

conclusions to a population

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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

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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

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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.

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Homework

● 2, 3 ● 4, 13, 14, 15, 24, ● 25 (Shadow02)

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