NO.PZ2024082801000045
问题如下:
Question A regression model is estimated using the equation Y = b0 + b1X1 + b2X2 + b3X3 + ε, where regression statistics show that X1 and X2 are highly statistically significant but X3 is not statistically significant. Which of the following statements about the use of this model for prediction is most accurate?选项:
A.A.The model should not be used for prediction because X3 is not statistically significant B.B. X3 should be excluded from the prediction equation since it is not statistically significant C.C. X3 should be included in the prediction equation since it was used in estimating the slope coefficients解释:
A is Incorrect because the model can still be used for prediction even if X3 is not statistically significant. If a regression model is estimated using all three independent variables, for example, any prediction of the dependent variable must also include all three variables—even the ones that are not statistically significant. This is because correlations between these variables were used in estimating the slope coefficients.
B is Incorrect because, if a regression model is estimated using all three independent variables, for example, any prediction of the dependent variable must also include all three variables—even the ones that are not statistically significant. This is because correlations between these variables were used in estimating the slope coefficients.
C is Correct because, if a regression model is estimated using all three independent variables, for example, any prediction of the dependent variable must also include all three variables—even the ones that are not statistically significant. This is because correlations between these variables were used in estimating the slope coefficients.
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