Unformatted text preview: Welcome to IM 541 Business Statistics Professor Eddine Dahel, Ph.D. Syllabus Slide 1 Chapter 1 Data and Statistics
s s s s s s What is Statistics Applications in Business and Economics Data Data Sources Descriptive Statistics Statistical Inference If I had only one day to live, I would live it in my statistics class it would seem so much longer. I need help! Slide 2 What is Statistics?
s s s Two meanings: Numerical data for example vital statistics on births, deaths, marriages, divorces, diseases, crime , education, welfare etc. The methodology for collection, presentation, and analysis of Data. The aim of statistics is to provide insight by means of data analysis whenever conditions of uncertainty prevail. Statistics involves three kinds of activities: Organizing, describing and p Organizing, describing and presenting data. Producing data. Drawing conclusions from d Drawing conclusions from data. Slide 3 Applications in Business and Economics
s Accounting Public accounting firms use statistical sampling procedures when conducting audits for their clients. s Economics Economists use statistical information in making forecasts about the future of the economy or some aspect of it. Slide 4 Applications in Business and Economics
s Marketing Electronic pointofsale scanners at retail checkout counters are used to collect data for a variety of marketing research applications. s Production A variety of statistical quality control charts are used to monitor the output of a production process. Slide 5 Applications in Business and Economics Finance Financial advisors use priceearnings ratios and dividend yields to guide their investment recommendations. Slide 6 Data and Data Sets Data are the facts and figures collected, summarized, analyzed, and interpreted.
s The data collected in a particular study are referred to as the data set. Slide 7 Elements, Variables, and Observations The elements are the entities on which data are collected. A variable is a characteristic of interest for the elements. The set of measurements collected for a particular element is called an observation. The total number of data values in a data set is the number of elements multiplied by the number of variables. Slide 8 Data, Data Sets, Elements, Variables, and Observations
Elements Variables Company Dataram EnergySouth Keystone LandCare Psychemedics Stock Annual Earn/ Exchange Sales($M) Share($) AMEX OTC NYSE NYSE AMEX 73.10 0.86 74.00 1.67 365.70 0.86 111.40 0.33 17.60 0.13
Data Set Slide 9 Qualitative and Quantitative Data Data can be further classified as being qualitative or quantitative. The statistical analysis that is appropriate depends on whether the data for the variable are qualitative or quantitative. In general, there are more alternatives for statistical analysis when the data are quantitative. Slide 10 Qualitative Data Labels or names used to identify an attribute of each element Often referred to as categorical data Can be either numeric or nonnumeric Appropriate statistical analyses are rather limited Slide 11 Quantitative Data Quantitative data indicate how many or how much: discrete, if measuring how many continuous, if measuring how much Quantitative data are always numeric. Ordinary arithmetic operations are meaningful for quantitative data. Slide 12 CrossSectional and Time Series Data Crosssectional data are collected at the same or approximately the same point in time. Example: data detailing the number of building permits issued in June 2006 in each of the counties of California Slide 13 CrossSectional and Time Series Data Time series data are collected over several time periods. Example: data detailing the number of building permits issued in Monterey County, in each of the last 36 months Slide 14 Data Sources
s Existing Sources Within a firm almost any department Business database services Dow Jones & Co. Government agencies U.S. Department of Labor Industry associations Travel Industry Association of America Specialinterest organizations Graduate Management Admission Council Internet more and more firms Slide 15 Data Sources
s Statistical Studies In experimental studies the variables of interest are first identified. Then one or more factors are controlled so that data can be obtained about how the factors influence the variables. In observational (nonexperimental) studies no attempt is made to control or influence the variables of interest. a survey is a good example Slide 16 Data Acquisition Considerations
Time Requirement Searching for information can be time consuming. Information may no longer be useful by the time it
is available. Cost of Acquisition Organizations often charge for information even when it is not their primary business activity. Data Errors Using any data that happens to be available or that were acquired with little care can lead to poor and misleading information. Slide 17 Two Branches of Statistics
s Descriptive statistics are the tabular, graphical, and numerical methods used to summarize data. The most common numerical descriptive statistics the average (or mean). Statistical Inference the process of using data obtained from a sample to make estimates and test hypotheses about the characteristics of a population s Slide 18 End of Chapter 1 Slide 19 ...
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- Spring '08