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Linear Regression - Estimating Parameters Bernd Schr oder logo1 - PowerPoint PPT Presentation

Coefficients Examples Error Sum of Squares Coefficient of Determination Linear Regression - Estimating Parameters Bernd Schr oder logo1 Bernd Schr oder Louisiana Tech University, College of Engineering and Science Linear Regression -


  1. Coefficients Examples Error Sum of Squares Coefficient of Determination n n ∂ f = ∂ [ y i − ( b 0 + b 1 x i )] ! [ y i − ( b 0 + b 1 x i )] 2 ∑ ∑ = − 2 = 0 ∂ b 0 ∂ b 0 i = 1 i = 1 n n ∂ f = ∂ x i [ y i − ( b 0 + b 1 x i )] ! [ y i − ( b 0 + b 1 x i )] 2 ∑ ∑ = = 0 − 2 ∂ b 1 ∂ b 1 i = 1 i = 1 n n ∑ ∑ y i − nb 0 − b 1 x i = 0 i = 1 i = 1 n n n x 2 ∑ ∑ ∑ = x i y i − b 0 x i − b 1 0 i i = 1 i = 1 i = 1 n n ∑ ∑ nb 0 + b 1 x i = y i i = 1 i = 1 n n n x 2 ∑ ∑ ∑ x i + b 1 = b 0 x i y i i i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  2. Coefficients Examples Error Sum of Squares Coefficient of Determination logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  3. Coefficients Examples Error Sum of Squares Coefficient of Determination n n ∑ ∑ nb 0 + b 1 = x i y i i = 1 i = 1 n n n ∑ ∑ x 2 ∑ b 0 x i + b 1 = x i y i i i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  4. Coefficients Examples Error Sum of Squares Coefficient of Determination n n ∑ ∑ nb 0 + b 1 = x i y i i = 1 i = 1 n n n ∑ ∑ x 2 ∑ b 0 x i + b 1 = x i y i i i = 1 i = 1 i = 1 � � n n 1 ∑ ∑ = b 0 y i − b 1 x i n i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  5. Coefficients Examples Error Sum of Squares Coefficient of Determination n n ∑ ∑ nb 0 + b 1 = x i y i i = 1 i = 1 n n n ∑ ∑ x 2 ∑ b 0 x i + b 1 = x i y i i i = 1 i = 1 i = 1 � � n n 1 ∑ ∑ = b 0 y i − b 1 x i n i = 1 i = 1 � � n n n n n 1 x 2 ∑ ∑ ∑ ∑ ∑ x i + b 1 = y i − b 1 x i x i y i i n i = 1 i = 1 i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  6. Coefficients Examples Error Sum of Squares Coefficient of Determination n n ∑ ∑ nb 0 + b 1 = x i y i i = 1 i = 1 n n n ∑ ∑ x 2 ∑ b 0 x i + b 1 = x i y i i i = 1 i = 1 i = 1 � � n n 1 ∑ ∑ = b 0 y i − b 1 x i n i = 1 i = 1 � � n n n n n 1 x 2 ∑ ∑ ∑ ∑ ∑ x i + b 1 = y i − b 1 x i x i y i i n i = 1 i = 1 i = 1 i = 1 i = 1  � 2  � n n n n n i − 1 x i y i − 1 x 2 ∑ ∑ ∑ ∑ ∑ b 1 x i = y i x i   n n i = 1 i = 1 i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  7. Coefficients Examples Error Sum of Squares Coefficient of Determination logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  8. Coefficients Examples Error Sum of Squares Coefficient of Determination ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n i = 1 x i = b 1 � i = 1 x i ) 2 � ∑ n i − 1 n ( ∑ n i = 1 x 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  9. Coefficients Examples Error Sum of Squares Coefficient of Determination ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n i = 1 x i = b 1 � i = 1 x i ) 2 � ∑ n i − 1 n ( ∑ n i = 1 x 2 ∑ n i = 1 x i y i − ∑ n i = 1 y i x = � ∑ n i = 1 x 2 i − ∑ n � i = 1 x i x logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  10. Coefficients Examples Error Sum of Squares Coefficient of Determination ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n i = 1 x i = b 1 � i = 1 x i ) 2 � ∑ n i − 1 n ( ∑ n i = 1 x 2 ∑ n i = 1 x i y i − ∑ n i = 1 y i x = � ∑ n i = 1 x 2 i − ∑ n � i = 1 x i x ∑ n i = 1 y i ( x i − x ) − ∑ n i = 1 y ( x i − x ) = ∑ n i = 1 x i ( x i − x ) − ∑ n i = 1 x ( x i − x ) logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  11. Coefficients Examples Error Sum of Squares Coefficient of Determination ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n i = 1 x i = b 1 � i = 1 x i ) 2 � ∑ n i − 1 n ( ∑ n i = 1 x 2 ∑ n i = 1 x i y i − ∑ n i = 1 y i x = � ∑ n i = 1 x 2 i − ∑ n � i = 1 x i x ∑ n i = 1 y i ( x i − x ) − ∑ n i = 1 y ( x i − x ) = ∑ n i = 1 x i ( x i − x ) − ∑ n i = 1 x ( x i − x ) ∑ n i = 1 ( x i − x )( y i − y ) = i = 1 ( x i − x ) 2 ∑ n logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  12. Coefficients Examples Error Sum of Squares Coefficient of Determination ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n i = 1 x i = b 1 � i = 1 x i ) 2 � ∑ n i − 1 n ( ∑ n i = 1 x 2 ∑ n i = 1 x i y i − ∑ n i = 1 y i x = � ∑ n i = 1 x 2 i − ∑ n � i = 1 x i x ∑ n i = 1 y i ( x i − x ) − ∑ n i = 1 y ( x i − x ) = ∑ n i = 1 x i ( x i − x ) − ∑ n i = 1 x ( x i − x ) ∑ n i = 1 ( x i − x )( y i − y ) = i = 1 ( x i − x ) 2 ∑ n = b 0 y − b 1 x logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  13. Coefficients Examples Error Sum of Squares Coefficient of Determination Summarizing the Formulas logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  14. Coefficients Examples Error Sum of Squares Coefficient of Determination Summarizing the Formulas 1. b 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  15. Coefficients Examples Error Sum of Squares Coefficient of Determination Summarizing the Formulas 1. b 1 = ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n i = 1 x i � i = 1 x i ) 2 � ∑ n i − 1 n ( ∑ n i = 1 x 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  16. Coefficients Examples Error Sum of Squares Coefficient of Determination Summarizing the Formulas 1. b 1 = ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n = ∑ n i = 1 x i i = 1 ( x i − x )( y i − y ) � i = 1 x i ) 2 � i = 1 ( x i − x ) 2 ∑ n ∑ n i − 1 n ( ∑ n i = 1 x 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  17. Coefficients Examples Error Sum of Squares Coefficient of Determination Summarizing the Formulas 1. b 1 = ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n = ∑ n i = 1 x i i = 1 ( x i − x )( y i − y ) = S xy � i = 1 x i ) 2 � i = 1 ( x i − x ) 2 ∑ n S xx ∑ n i − 1 n ( ∑ n i = 1 x 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  18. Coefficients Examples Error Sum of Squares Coefficient of Determination Summarizing the Formulas 1. b 1 = ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n = ∑ n i = 1 x i i = 1 ( x i − x )( y i − y ) = S xy � i = 1 x i ) 2 � i = 1 ( x i − x ) 2 ∑ n S xx ∑ n i − 1 n ( ∑ n i = 1 x 2 2. b 0 = y − b 1 x logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  19. Coefficients Examples Error Sum of Squares Coefficient of Determination Summarizing the Formulas 1. b 1 = ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n = ∑ n i = 1 x i i = 1 ( x i − x )( y i − y ) = S xy � i = 1 x i ) 2 � i = 1 ( x i − x ) 2 ∑ n S xx ∑ n i − 1 n ( ∑ n i = 1 x 2 2. b 0 = y − b 1 x y i : = ˆ β 0 + ˆ β 1 x i . 3. Fitted (or predicted) values: ˆ logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  20. Coefficients Examples Error Sum of Squares Coefficient of Determination Summarizing the Formulas 1. b 1 = ∑ n i = 1 x i y i − 1 n ∑ n i = 1 y i ∑ n = ∑ n i = 1 x i i = 1 ( x i − x )( y i − y ) = S xy � i = 1 x i ) 2 � i = 1 ( x i − x ) 2 ∑ n S xx ∑ n i − 1 n ( ∑ n i = 1 x 2 2. b 0 = y − b 1 x y i : = ˆ β 0 + ˆ β 1 x i . 3. Fitted (or predicted) values: ˆ 4. Residuals: y i − ˆ y i . logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  21. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  22. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  23. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  24. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  25. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  26. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  27. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  28. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  29. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  30. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  31. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  32. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  33. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  34. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  35. Coefficients Examples Error Sum of Squares Coefficient of Determination How Well Does the Line Fit the Data? logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  36. Coefficients Examples Error Sum of Squares Coefficient of Determination How Well Does the Line Fit the Data? 1. Error sum of squares (or residual sum of squares). logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  37. Coefficients Examples Error Sum of Squares Coefficient of Determination How Well Does the Line Fit the Data? 1. Error sum of squares (or residual sum of squares). n n �� 2 y i ) 2 = � � β 0 + ˆ ˆ ∑ ∑ SSE = ( y i − ˆ β 1 x i y i − i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  38. Coefficients Examples Error Sum of Squares Coefficient of Determination How Well Does the Line Fit the Data? 1. Error sum of squares (or residual sum of squares). n n �� 2 y i ) 2 = � � β 0 + ˆ ˆ ∑ ∑ SSE = ( y i − ˆ β 1 x i y i − i = 1 i = 1 Estimate of σ 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  39. Coefficients Examples Error Sum of Squares Coefficient of Determination How Well Does the Line Fit the Data? 1. Error sum of squares (or residual sum of squares). n n �� 2 y i ) 2 = � � β 0 + ˆ ˆ ∑ ∑ SSE = ( y i − ˆ β 1 x i y i − i = 1 i = 1 y i ) 2 n − 2 = ∑ n i = 1 ( y i − ˆ σ 2 = s 2 = SSE Estimate of σ 2 : ˆ . n − 2 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  40. Coefficients Examples Error Sum of Squares Coefficient of Determination How Well Does the Line Fit the Data? 1. Error sum of squares (or residual sum of squares). n n �� 2 y i ) 2 = � � β 0 + ˆ ˆ ∑ ∑ SSE = ( y i − ˆ β 1 x i y i − i = 1 i = 1 y i ) 2 n − 2 = ∑ n i = 1 ( y i − ˆ σ 2 = s 2 = SSE Estimate of σ 2 : ˆ . n − 2 2. We divide by n − 2 because we have only n − 2 degrees of freedom after determining two parameters ˆ β 0 and ˆ β 1 . logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  41. Coefficients Examples Error Sum of Squares Coefficient of Determination How Well Does the Line Fit the Data? 1. Error sum of squares (or residual sum of squares). n n �� 2 y i ) 2 = � � β 0 + ˆ ˆ ∑ ∑ SSE = ( y i − ˆ β 1 x i y i − i = 1 i = 1 y i ) 2 n − 2 = ∑ n i = 1 ( y i − ˆ σ 2 = s 2 = SSE Estimate of σ 2 : ˆ . n − 2 2. We divide by n − 2 because we have only n − 2 degrees of freedom after determining two parameters ˆ β 0 and ˆ β 1 . (Previously, using an estimate of µ resulted in the loss of one degree of freedom.) logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  42. Coefficients Examples Error Sum of Squares Coefficient of Determination How Well Does the Line Fit the Data? 1. Error sum of squares (or residual sum of squares). n n �� 2 y i ) 2 = � � β 0 + ˆ ˆ ∑ ∑ SSE = ( y i − ˆ β 1 x i y i − i = 1 i = 1 y i ) 2 n − 2 = ∑ n i = 1 ( y i − ˆ σ 2 = s 2 = SSE Estimate of σ 2 : ˆ . n − 2 2. We divide by n − 2 because we have only n − 2 degrees of freedom after determining two parameters ˆ β 0 and ˆ β 1 . (Previously, using an estimate of µ resulted in the loss of one degree of freedom.) 3. It can be shown (we cannot present the proof) that S 2 is an unbiased estimator for σ 2 . logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  43. Coefficients Examples Error Sum of Squares Coefficient of Determination Formula For SSE logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  44. Coefficients Examples Error Sum of Squares Coefficient of Determination Formula For SSE SSE logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  45. Coefficients Examples Error Sum of Squares Coefficient of Determination Formula For SSE n y i ) 2 ∑ = ( y i − ˆ SSE i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  46. Coefficients Examples Error Sum of Squares Coefficient of Determination Formula For SSE n y i ) 2 ∑ = ( y i − ˆ SSE i = 1 n �� 2 � � β 0 + ˆ ˆ ∑ = y i − β 1 x i i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  47. Coefficients Examples Error Sum of Squares Coefficient of Determination Formula For SSE n y i ) 2 ∑ = ( y i − ˆ SSE i = 1 n �� 2 � � β 0 + ˆ ˆ ∑ = y i − β 1 x i i = 1 n i − 2 ˆ β 0 y i − 2 ˆ β 1 x i y i + ˆ 0 + 2 ˆ β 0 ˆ β 1 x i + ˆ y 2 β 2 β 2 1 x 2 ∑ = i i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  48. Coefficients Examples Error Sum of Squares Coefficient of Determination Formula For SSE n y i ) 2 ∑ = ( y i − ˆ SSE i = 1 n �� 2 � � β 0 + ˆ ˆ ∑ = y i − β 1 x i i = 1 n i − 2 ˆ β 0 y i − 2 ˆ β 1 x i y i + ˆ 0 + 2 ˆ β 0 ˆ β 1 x i + ˆ y 2 β 2 β 2 1 x 2 ∑ = i i = 1 n n n n n i − 2 ˆ y i − 2 ˆ x i y i + n ˆ 0 + 2 ˆ β 0 ˆ x i + ˆ ∑ y 2 ∑ ∑ β 2 ∑ β 2 ∑ x 2 = β 0 β 1 β 1 1 i i = 1 i = 1 i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  49. Coefficients Examples Error Sum of Squares Coefficient of Determination Formula For SSE n n n n n i − 2 ˆ y i − 2 ˆ x i y i + n ˆ 0 + 2 ˆ β 0 ˆ x i + ˆ y 2 β 2 β 2 x 2 ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE 1 i i = 1 i = 1 i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  50. Coefficients Examples Error Sum of Squares Coefficient of Determination Formula For SSE n n n n n i − 2 ˆ y i − 2 ˆ x i y i + n ˆ 0 + 2 ˆ β 0 ˆ x i + ˆ y 2 β 2 β 2 x 2 ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE 1 i i = 1 i = 1 i = 1 i = 1 i = 1 � � n n n n n y 2 i − 2 ˆ y i − 2 ˆ x i y i + ˆ y i − ˆ ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 0 β 1 x i i = 1 i = 1 i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  51. Coefficients Examples Error Sum of Squares Coefficient of Determination Formula For SSE n n n n n i − 2 ˆ y i − 2 ˆ x i y i + n ˆ 0 + 2 ˆ β 0 ˆ x i + ˆ y 2 β 2 β 2 x 2 ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE 1 i i = 1 i = 1 i = 1 i = 1 i = 1 � � n n n n n y 2 i − 2 ˆ y i − 2 ˆ x i y i + ˆ y i − ˆ ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 0 β 1 x i i = 1 i = 1 i = 1 i = 1 i = 1 n n + 2 ˆ β 0 ˆ x i + ˆ β 2 x 2 ∑ ∑ β 1 1 i i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  52. Coefficients Examples Error Sum of Squares Coefficient of Determination Formula For SSE n n n n n i − 2 ˆ y i − 2 ˆ x i y i + n ˆ 0 + 2 ˆ β 0 ˆ x i + ˆ y 2 β 2 β 2 x 2 ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE 1 i i = 1 i = 1 i = 1 i = 1 i = 1 � � n n n n n y 2 i − 2 ˆ y i − 2 ˆ x i y i + ˆ y i − ˆ ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 0 β 1 x i i = 1 i = 1 i = 1 i = 1 i = 1 n n + 2 ˆ β 0 ˆ x i + ˆ β 2 x 2 ∑ ∑ β 1 1 i i = 1 i = 1 n n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ x i + ˆ y 2 β 2 x 2 ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 1 1 i i = 1 i = 1 i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  53. Coefficients Examples Error Sum of Squares Coefficient of Determination n n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ x i + ˆ y 2 β 2 x 2 ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE 1 i i = 1 i = 1 i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  54. Coefficients Examples Error Sum of Squares Coefficient of Determination n n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ x i + ˆ y 2 β 2 x 2 ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE 1 i i = 1 i = 1 i = 1 i = 1 i = 1 n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ ∑ y 2 ∑ ∑ ∑ = β 0 β 1 β 1 x i i = 1 i = 1 i = 1 i = 1  � 2  � n n i ± 1 + ˆ β 2 x 2 ∑ ∑ x i 1   n i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  55. Coefficients Examples Error Sum of Squares Coefficient of Determination n n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ x i + ˆ y 2 β 2 x 2 ∑ ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE 1 i i = 1 i = 1 i = 1 i = 1 i = 1 n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ ∑ y 2 ∑ ∑ ∑ = β 0 β 1 β 1 x i i = 1 i = 1 i = 1 i = 1  � 2  � n n i ± 1 + ˆ β 2 x 2 ∑ ∑ x i 1   n i = 1 i = 1 n n n n y 2 i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ ∑ ∑ ∑ ∑ = β 0 β 1 β 1 x i i = 1 i = 1 i = 1 i = 1  � 2  � 2 � � n n n i − 1 1 + ˆ β 2 x 2  + ˆ β 2 ∑ ∑ ∑ x i x i 1  1 n n i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  56. Coefficients Examples Error Sum of Squares Coefficient of Determination n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ y 2 ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE x i i = 1 i = 1 i = 1 i = 1  � 2  � 2 � � n n n i − 1 1 + ˆ β 2 x 2  + ˆ β 2 ∑ ∑ ∑ x i x i 1  1 n n i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  57. Coefficients Examples Error Sum of Squares Coefficient of Determination n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ y 2 ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE x i i = 1 i = 1 i = 1 i = 1  � 2  � 2 � � n n n i − 1 1 + ˆ β 2 x 2  + ˆ β 2 ∑ ∑ ∑ x i x i 1  1 n n i = 1 i = 1 i = 1 n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ ∑ y 2 ∑ ∑ ∑ = β 0 β 1 β 1 x i i = 1 i = 1 i = 1 i = 1 � 2 � � � n n n n x i y i − 1 1 + ˆ + ˆ β 2 ∑ ∑ ∑ ∑ β 1 y i x i x i 1 n n i = 1 i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  58. Coefficients Examples Error Sum of Squares Coefficient of Determination n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ y 2 ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE x i i = 1 i = 1 i = 1 i = 1 � 2 � � � n n n n x i y i − 1 1 + ˆ + ˆ β 2 ∑ ∑ ∑ ∑ β 1 y i x i x i 1 n n i = 1 i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  59. Coefficients Examples Error Sum of Squares Coefficient of Determination n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ y 2 ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE x i i = 1 i = 1 i = 1 i = 1 � 2 � � � n n n n x i y i − 1 1 + ˆ + ˆ β 2 ∑ ∑ ∑ ∑ β 1 y i x i x i 1 n n i = 1 i = 1 i = 1 i = 1 n n n n i − ˆ y i − ˆ x i y i + ˆ β 0 ˆ y 2 ∑ ∑ ∑ ∑ = β 0 β 1 β 1 x i i = 1 i = 1 i = 1 i = 1 � � n n n 1 1 − ˆ y i − ˆ ∑ ∑ ∑ β 1 β 1 x i x i n n i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  60. Coefficients Examples Error Sum of Squares Coefficient of Determination n n n n i − ˆ y i − 2 ˆ x i y i + ˆ β 0 ˆ y 2 ∑ ∑ ∑ ∑ = β 0 β 1 β 1 SSE x i i = 1 i = 1 i = 1 i = 1 � 2 � � � n n n n x i y i − 1 1 + ˆ + ˆ β 2 ∑ ∑ ∑ ∑ β 1 y i x i x i 1 n n i = 1 i = 1 i = 1 i = 1 n n n n i − ˆ y i − ˆ x i y i + ˆ β 0 ˆ y 2 ∑ ∑ ∑ ∑ = β 0 β 1 β 1 x i i = 1 i = 1 i = 1 i = 1 � � n n n 1 1 − ˆ y i − ˆ ∑ ∑ ∑ β 1 β 1 x i x i n n i = 1 i = 1 i = 1 n n n i − ˆ y i − ˆ ∑ y 2 ∑ ∑ = β 0 β 1 x i y i i = 1 i = 1 i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  61. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1. logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  62. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1. logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  63. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1. SSE ≈ 1 . 1194 and s 2 ≈ 0 . 0622 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  64. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2. logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  65. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2. logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  66. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2. SSE ≈ 79 . 7958 and s 2 ≈ 4 . 4331 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  67. Coefficients Examples Error Sum of Squares Coefficient of Determination Coefficient of Determination logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  68. Coefficients Examples Error Sum of Squares Coefficient of Determination Coefficient of Determination n ( y i − y ) 2 be the total sum of squares. ∑ 1. Let SST : = i = 1 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  69. Coefficients Examples Error Sum of Squares Coefficient of Determination Coefficient of Determination n ( y i − y ) 2 be the total sum of squares. The ∑ 1. Let SST : = i = 1 coefficient of determination is given by r 2 = 1 − SSE SST . logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  70. Coefficients Examples Error Sum of Squares Coefficient of Determination Coefficient of Determination n ( y i − y ) 2 be the total sum of squares. The ∑ 1. Let SST : = i = 1 coefficient of determination is given by r 2 = 1 − SSE SST . 2. SSE measures how much variation is not attributed to the linear relationship. logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  71. Coefficients Examples Error Sum of Squares Coefficient of Determination Coefficient of Determination n ( y i − y ) 2 be the total sum of squares. The ∑ 1. Let SST : = i = 1 coefficient of determination is given by r 2 = 1 − SSE SST . 2. SSE measures how much variation is not attributed to the linear relationship. 3. SST measures the total variation in y . logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  72. Coefficients Examples Error Sum of Squares Coefficient of Determination Coefficient of Determination n ( y i − y ) 2 be the total sum of squares. The ∑ 1. Let SST : = i = 1 coefficient of determination is given by r 2 = 1 − SSE SST . 2. SSE measures how much variation is not attributed to the linear relationship. 3. SST measures the total variation in y . 4. The quotient gives the proportion of the variation not attributed to the linear relationship. logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  73. Coefficients Examples Error Sum of Squares Coefficient of Determination Coefficient of Determination n ( y i − y ) 2 be the total sum of squares. The ∑ 1. Let SST : = i = 1 coefficient of determination is given by r 2 = 1 − SSE SST . 2. SSE measures how much variation is not attributed to the linear relationship. 3. SST measures the total variation in y . 4. The quotient gives the proportion of the variation not attributed to the linear relationship. 5. r 2 gives the proportion of the variation that is attributed to the linear relationship. logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  74. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1. logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  75. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1. logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  76. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 1. r 2 ≈ . 9516 logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

  77. Coefficients Examples Error Sum of Squares Coefficient of Determination Example 2. logo1 Bernd Schr¨ oder Louisiana Tech University, College of Engineering and Science Linear Regression - Estimating Parameters

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