150 likes | 865 Views
Introduction to Statistics. BUSA 2100, Sect. 1.0, 1.2 - 1.5 Dr. Moore. Definition of Statistics. Many people think of statistics as large amounts of numerical data, e.g. stock prices, sports statistics.
E N D
Introduction to Statistics BUSA 2100, Sect. 1.0, 1.2 - 1.5 Dr. Moore
Definition of Statistics • Many people think of statistics as large amounts of numerical data, e.g. stock prices, sports statistics. • Definition: The academic discipline of statistics is the study of how data are collected, analyzed, summarized, presented, and interpreted.
Why Study Statistics? • 1.Statistics are widely used in bus-iness. Usage continues to increase as the business world becomes larger, more complex, and more quantitative. • 2.Statistics provide data and tools for better quality decision making.
Why Study Stat? / Definitions • 3. Decisions made using quantitative data tend to be more accurate, more objective, and more easily defended. • Definition: Data are facts and figures. • Qualitative or categorical data: labels, names, non-numeric descriptions, and numeric codes. (State examples.)
More About Data • Quantitative data: always numeric; indicate how much or how many. • Where do data come from? We will consider 5 source categories. • 1. Internal business records: personnel records, sales records, inventory records, financial statements
Sources of Data • 2. Internet: company web sites • 3. Experimental studies: prescription drug comparisons, agricultural plots • 4. Governmental agencies: Dept. of Labor (wages, employment rates); Census Bureau (populations, data about households). • 5. Surveys: Questionnaires or interviews to obtain information about topics of interest.
Branches of Statistics • The academic discipline of statistics can be divided into two major branches: descriptive and inferential statistics. • Descriptive statistics: Deals with summarizing and presenting data in a readable, easily understood form. • Ex.:Graphs, tables, charts, averages
Descriptive Stat. Example • Example: Daily high temperatures in Atlanta for the past 10 years; N = 3,650.
Inferential Statistics • The amount of data has been greatly reduced and is much easier to under-stand. • Inferential statistics: Drawing conclusions about a population based on information from a sample.
Populations and Samples • Population: Set of all items of interest in a particular study. • Sample: A subset (portion) of the population. • Examples of inferential statistics: Nielsen TV ratings surveys, political preference polls.