PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 1 1 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 2 Regression Analysis Year X Y 1 10 44 2 9 40 3 11 42 4 12 46 5 11 48 6 12 52 7 13 54 8 13 58 9 14 56 10 15 60 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Scatter Diagram Copyright 2007 by Oxford University Press, Inc. Slide 3 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 4 Regression Analysis • Regression Line: Line of Best Fit • Regression Line: Minimizes the sum of the squared vertical deviations (et) of each point from the regression line. • Ordinary Least Squares (OLS) Method PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 5 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 6 Ordinary Least Squares (OLS) Model: Yt a bX t et € Y€t a€ bX t et Yt Y€t PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 7 Ordinary Least Squares (OLS) Objective: Determine the slope and intercept that minimize the sum of the squared errors. n n n t 1 t 1 t 1 2 2 € )2 € € e ( Y Y ) ( Y a bX t t t t t PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 8 Ordinary Least Squares (OLS) Estimation Procedure n b€ (X t 1 t X )(Yt Y ) n 2 ( X X ) t € a€ Y bX t 1 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 9 Ordinary Least Squares (OLS) Estimation Example Time Xt 1 2 3 4 5 6 7 8 9 10 10 9 11 12 11 12 13 13 14 15 120 n 10 Yt 44 40 42 46 48 52 54 58 56 60 500 n n X t 120 Yt 500 t 1 n X t 1 X t 120 12 n 10 t 1 n Yt 500 50 10 t 1 n Y PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Xt X Yt Y -2 -3 -1 0 -1 0 1 1 2 3 -6 -10 -8 -4 -2 2 4 8 6 10 n (X t 1 t 1 ( X t X )2 12 30 8 0 2 0 4 8 12 30 106 4 9 1 0 1 0 1 1 4 9 30 t X ) 2 30 106 b€ 3.533 30 t X )(Yt Y ) 106 a€ 50 (3.533)(12) 7.60 n (X ( X t X )(Yt Y ) Copyright 2007 by Oxford University Press, Inc. Slide 10 Ordinary Least Squares (OLS) Estimation Example n X n 10 n X t 1 t n (X t 1 t 1 120 n Y t 1 t n 500 Yt 500 50 10 t 1 n Y t X ) 30 106 € b 3.533 30 t X )(Yt Y ) 106 a€ 50 (3.533)(12) 7.60 2 n (X t 1 X t 120 12 n 10 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 11 Tests of Significance Standard Error of the Slope Estimate sbˆ 2 ˆ (Yt Y ) (n k ) ( X t X ) PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. 2 e (n k ) ( X Copyright 2007 by Oxford University Press, Inc. 2 t t X )2 Slide 12 Tests of Significance Example Calculation Y€t et Yt Y€t et2 (Yt Y€t )2 ( X t X )2 44 42.90 1.10 1.2100 4 9 40 39.37 0.63 0.3969 9 3 11 42 46.43 -4.43 19.6249 1 4 12 46 49.96 -3.96 15.6816 0 5 11 48 46.43 1.57 2.4649 1 6 12 52 49.96 2.04 4.1616 0 7 13 54 53.49 0.51 0.2601 1 8 13 58 53.49 4.51 20.3401 1 9 14 56 57.02 -1.02 1.0404 4 10 15 60 60.55 -0.55 0.3025 9 65.4830 30 Time Xt Yt 1 10 2 n n e (Yt Y€t )2 65.4830 t 1 2 t t 1 (X t 1 (Y Y€) ( n k ) ( X X ) 2 n X ) 30 2 t PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. sb€ t 2 t Copyright 2007 by Oxford University Press, Inc. 65.4830 0.52 (10 2)(30) Slide 13 Tests of Significance Example Calculation n n t 1 t 1 2 2 € e ( Y Y ) t t t 65.4830 n 2 ( X X ) 30 t t 1 2 € (Yt Y ) 65.4830 sb€ 0.52 2 ( n k ) ( X t X ) (10 2)(30) PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 14 Tests of Significance Calculation of the t Statistic b€ 3.53 t 6.79 sb€ 0.52 Degrees of Freedom = (n-k) = (10-2) = 8 Critical Value at 5% level =2.306 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 15 Tests of Significance Decomposition of Sum of Squares Total Variation = Explained Variation + Unexplained Variation 2 2 € € (Yt Y ) (Y Y ) (Yt Yt ) 2 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 16 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 17 Tests of Significance Coefficient of Determination R2 2 € ( Y Y ) Explained Variation 2 TotalVariation ( Y Y ) t 373.84 R 0.85 440.00 2 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 18 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 19 Tests of Significance Coefficient of Correlation r R 2 withthe sign of b€ 1 r 1 r 0.85 0.92 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 20 Chapter 4 Appendix PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 21 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 22 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 23 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 24 Getting Started • Install the Analysis ToolPak add-in from the Excel installation media if it has not already been installed • Attach the Analysis ToolPak add-in – From the menu, select Tools and then Add-Ins... – When the Add-Ins dialog appears, select Analysis ToolPak and then click OK. PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 25 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 26 Entering Data • Data on each variable must be entered in a separate column • Label the top of each column with a symbol or brief description to identify the variable • Multiple regression analysis requires that all data on independent variables be in adjacent columns PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 27 Example Data PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 28 Running the Regression • Select the Regression tool from the Analysis ToolPak dialog – From the menu, select Tools and then Data Analysis... – On the Data Analysis dialog, scroll down the list of Analysis Tools, select Regression, and then click OK – The Regression tool dialog will then be displayed PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 29 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 30 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 31 Select the Data Ranges • Type in the data range for the Y variable or select the range on the worksheet • Type in the data range for the X variable(s) or select the range on the worksheet • If your ranges include the data labels (recommended) then check the labels option PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 32 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 33 Select an Output Option • Output to a selected range – Selection is the upper left corner of the output range • Output to a new worksheet – Optionally enter a name for the worksheet • Output to a new workbook • And then click OK PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 34 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 35 Regression Output PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 36 Multiple Regression Data PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 37 PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 38 Regression Output PowerPoint Slides Prepared by Robert F. Brooker, Ph.D. Copyright 2007 by Oxford University Press, Inc. Slide 39