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Questions in bold: What is the average number of labor hours required for a move

ID: 3053769 • Letter: Q

Question

Questions in bold:

What is the average number of labor hours required for a move? (2 point

Write the theoretical linear model in equation form (3 points).

Write the estimated linear regression model in equation form (3 points).

Predict the labor hours for moving 500 cubic feet with 2 large pieces of furniture         (4 points)

Is the model statistically useful to explain and predict labor hours? Use a formal test and describe all the necessary steps (8 poi

Interpret the R2 (3 points)

What explanatory variables are statistically significant at the 5% level? (4 points)

Interpret the coefficient related to “feet” (cubic feet moved) (3 point)

Interpret the intercept (3 points).

Do cubic feet moved (feet) has a positive effect on sales? Use a formal test and describe all the necessary steps (8 points)

Calculate and interpret a 90% confidence interval for the effect of cubic feet moved (feet) on labor hours (8 points).

Is there a multicollinearity problem related to the variable “feet”? Calculate and interpret the VIF value (6 points)

Data:

The owner of a moving company typically has her most experienced manager predict the total number of labor hours that will be required to complete an upcoming move. This approach has proven useful in the past but the manager has the business objective of developing a more accurate method of predicting moving labor hours (y= hours) using regression analysis. The owner has decided to use the number of cubic feet moved (x1=feet) and the number of pieces of large furniture (x2=large) as explanatory variables.

Summary Statistics

Hours

Feet

Large

min

9.00

220.00

1.00

max

79.50

1397.00

7.00

mean

28.96

625.56

3.06

std. dev.

14.901

280.58

1.413

SUMMARY OUTPUT of regression of labor hours (dependent variable) on cubic feet moved and (feet) and number of pieces of large furniture moved (large)

Regression Statistics

Multiple R

0.966

R Square

0.933

Adjusted R Square

0.929

Standard Error

3.980

Observations

36.000

ANOVA

df

SS

MS

F

Significance F

Regression

2.000

7248.706

3624.353

228.805

0.000

Residual

33.000

522.732

15.840

Total

35.000

7771.438

Coefficients

Standard Error

t Stat

P-value

Lower 95%

Upper 95%

Intercept

-3.915

1.674

-2.339

0.026

-7.321

-0.510

Feet

0.032

0.005

6.934

0.000

0.023

0.041

Large

4.223

0.914

4.619

0.000

2.363

6.083

SUMMARY OUTPUT of regression of cubic feet moved (feet)(dependent variable) on number of pieces of large furniture moved (large)

Regression Statistics

Multiple R

0.85

R Square

0.73

Adjusted R Square

0.72

Standard Error

148.25

Observations

36.00

ANOVA

df

SS

MS

F

Significance F

Regression

1.00

2008170.09

2008170.09

91.37

0.00

Residual

34.00

747262.80

21978.32

Total

35.00

2755432.89

Coefficients

Standard Error

t Stat

P-value

Lower 95%

Upper 95%

Intercept

107.61

59.55

1.81

0.08

-13.42

228.63

Large

169.51

17.73

9.56

0.00

133.47

205.55

Hours

Feet

Large

min

9.00

220.00

1.00

max

79.50

1397.00

7.00

mean

28.96

625.56

3.06

std. dev.

14.901

280.58

1.413

Explanation / Answer

1. What is the average number of labor hours required for a move? (2 point)

Average number of labor hours needs are 28.96


2. Write the theoretical linear model in equation form (3 points).

labour hours = Intercept + beta1 * (cubic Feet moved) + beta2 * (number of pieces of large furniture moved)


3. Write the estimated linear regression model in equation form (3 points).

labours hours = -3.915 + 0.032*(cubic Feet moved)+4.223(number of pieces of large furniture moved)


4. Predict the labor hours for moving 500 cubic feet with 2 large pieces of furniture (4 points)

labours hours = -3.915 + 0.032*(cubic Feet moved)+4.223(number of pieces of large furniture moved)

Given
cubic Feet moved = 500
number of pieces of large furniture moved = 2

Required equation

labours hours = -3.915 + 0.032*(500)+4.223(2) = 20.531 hours