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Given that the fitted regression is Y = 76.40 -6.388X1 + 0.870X2,the standard error of b1 is 1.453,and n = 63.At α = .05,we can conclude that X1 is a significant predictor of Y.

A) True
B) False

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Heteroscedasticity exists when all the errors (residuals)have the same variance.

A) True
B) False

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The effect of a binary predictor is to shift the regression intercept.

A) True
B) False

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Part of a regression output is provided below.Some of the information has been omitted. Part of a regression output is provided below.Some of the information has been omitted.   The approximate value of F is: A)  1605.7. B)  0.9134. C)  89.66. D)  impossible to calculate with the given information. The approximate value of F is:


A) 1605.7.
B) 0.9134.
C) 89.66.
D) impossible to calculate with the given information.

E) None of the above
F) A) and D)

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There is one residual for each predictor in the regression model.

A) True
B) False

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Analyze the regression results below (n = 33 cars in 1993)using the concepts you have learned about multiple regression.Circle things of interest and write comments in the margin.Make a prediction for CityMPG for a car with EngSize = 2.5,ManTran = 1,Length = 184,Wheelbase = 104,Weight = 3000,and Domestic = 0 (show your work).The variables are CityMPG = city MPG (miles per gallon by EPA rating);EngSize = engine size (liters);ManTran = 1 if manual transmission available,0 otherwise;Length = vehicle length (inches);Wheelbase = vehicle wheelbase (inches);Weight = vehicle weight (pounds);Domestic = 1 if U.S.manufacturer,0 otherwise. Analyze the regression results below (n = 33 cars in 1993)using the concepts you have learned about multiple regression.Circle things of interest and write comments in the margin.Make a prediction for CityMPG for a car with EngSize = 2.5,ManTran = 1,Length = 184,Wheelbase = 104,Weight = 3000,and Domestic = 0 (show your work).The variables are CityMPG = city MPG (miles per gallon by EPA rating);EngSize = engine size (liters);ManTran = 1 if manual transmission available,0 otherwise;Length = vehicle length (inches);Wheelbase = vehicle wheelbase (inches);Weight = vehicle weight (pounds);Domestic = 1 if U.S.manufacturer,0 otherwise.

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The regression is significant overall (F...

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Heteroscedasticity of residuals in regression suggests that there is:


A) nonconstant variation in the errors.
B) multicollinearity among the predictors.
C) nonnormality in the errors.
D) lack of independence in successive errors.

E) A) and D)
F) A) and B)

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Which of the following would be most useful in checking the normality assumption of the errors in a regression model?


A) The t-statistics for the coefficients
B) The F-statistic from the ANOVA table
C) The histogram of residuals
D) The VIF statistics for the predictors

E) All of the above
F) A) and D)

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Which statement about leverage is incorrect?


A) Leverage refers to an observation's distance from the mean of X.
B) If n = 40 and k = 4 predictors,a leverage statistic of .15 would indicate high leverage.
C) If n = 180 and k = 3 predictors,a leverage statistic of .08 would indicate high leverage.

D) None of the above
E) B) and C)

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A binary (categorical)predictor should not be used along with nonbinary predictors.

A) True
B) False

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If you rerun a regression,omitting a predictor X5,which would be unlikely?


A) The new R2 will decline if X5 was a relevant predictor.
B) The new standard error will increase if X5 was a relevant predictor.
C) The remaining estimated β's will change if X5 was collinear with other predictors.
D) The numerator degrees of freedom for the F test will increase.

E) A) and D)
F) A) and C)

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