A local trucking company fitted a regression to relate the t

A local trucking company fitted a regression to relate the travel time (days) of its shipments as a function of the distance traveled (miles). The fitted regression is Time = -1.126 + 0.0214 Distance, based on a sample of 20 shipments. The estimated standard error of the slope is 0 0053. Find the value of the test statistic, t_stat, to test for zero slope When predictor variables are strongly related to each other, it is called and the of the regression estimates is questionable. Which of the following is NOT true of the standard error of the regression model? A fitted multiple regression equation is Y = 12 + 3X1 - 2X2 + 7X3 + 2X4. When X1 increases 2 units and X2 increases 2 units as well, while X3 and X4 remain unchanged, what change would you expect in your estimate of Y? To check for normality of the residuals in a linear regression analysis, we can do:

Solution

7) Estimated std error = 0.0053

n = 20 shipments

Time = -1.126 + 0.0214 Distance

Slope = 0.0214

Test stat = slope/std error = 0.0214/0.0053 = 4.04

Ans) C 4.04

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8) D Multicollinearity, Stability

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9) D It is used in constructing confidence and prediction intervals for Y

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10) C Increase by 2

Since slope of X₁ is 3 - Increase of 2 units would result in Y increasing by 3*2 = 6 units

Since slope of X₂ is -2 - Increase of 2 units would result in Y increasing by -2*2 = -4 units

Hence overall an increase in 2 units

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11) E Either B or C

Durbin Watson is used for auto correaltion check