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732G21/732G28/732A35. Lecture 4. Variance-covariance matrix for the regression coefficients. Variance-covariance matrix of the model errors/residuals. and. where. Multiple regression model (theoretical). Multiple regression model (for a sample ). ANOVA table for multiple regression.
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732G21/732G28/732A35 Lecture 4
Variance-covariance matrix of the model errors/residuals and where
Multiple regression model (theoretical) Multiple regression model (for a sample)
ANOVA table for multiple regression where J is a n * n matrix of ones
Example data set (car prices) We have collected information about cars of a certain model. n = 59
Regression output from car example Regression Analysis: Price versus Year, Kilometers The regression equation is Price = - 35397446 + 17928 Year - 2.61 Kilometers Predictor Coef SE Coef T P Constant -35397446 5767248 -6.14 0.000 Year 17928 2881 6.22 0.000 Kilometers -2.6149 0.2039 -12.83 0.000 S = 30028.2 R-Sq = 90.2% R-Sq(adj) = 89.9% Analysis of Variance Source DF SS MS F P Regression 2 4.65369E+11 2.32684E+11 258.05 0.000 Residual Error 56 50494815376 901693132 Total 58 5.15864E+11
Interval estimation for multiple regression Confidence interval: where Prediction interval: where
Regression Analysis: Price versus Year, Kilometers The regression equation is Price = - 35397446 + 17928 Year - 2.61 Kilometers Predictor Coef SE Coef T P Constant -35397446 5767248 -6.14 0.000 Year 17928 2881 6.22 0.000 Kilometers -2.6149 0.2039 -12.83 0.000 S = 30028.2 R-Sq = 90.2% R-Sq(adj) = 89.9% Analysis of Variance Source DF SS MS F P Regression 2 4.65369E+11 2.32684E+11 258.05 0.000 Residual Error 56 50494815376 901693132 Total 58 5.15864E+11 Predicted Values for New Observations New Obs Fit SE Fit 95% CI 95% PI 1 415141 7201 (400716, 429567) (353282, 477001) Values of Predictors for New Observations New Obs Year Kilometers 1 2002 30000
Regression Analysis: Price versus Year, Kilometers, Equipment The regression equation is Price = - 20833056 + 10618 Year - 2.08 Kilometers + 57904 Equipment Predictor Coef SE Coef T P Constant -20833056 6309217 -3.30 0.002 Year 10618 3154 3.37 0.001 Kilometers -2.0768 0.2022 -10.27 0.000 Equipment 57904 10408 5.56 0.000 S = 29269.6 R-Sq = 90.0% R-Sq(adj) = 89.4% Analysis of Variance Source DF SS MS F P Regression 3 4.22692E+11 1.40897E+11 164.46 0.000 Residual Error 55 47118909984 856707454 Total 58 4.69810E+11 Source DF Seq SS Year 1 2.82889E+11 Kilometers 1 1.13288E+11 Equipment 1 26514947048