A microeconomist wants to determine how corporate sales are influenced by capital and wage spending by companies. She proceeds to randomly select 26 large corporations and record information in millions of dollars. The Microsoft Excel output below shows results of this multiple regression. SUMMARY OUTPUT
Regression Statistics
Multiple-R 0.830
R-Square 0.689
Adjusted-R-Square 0.662
Standard-Error 17501.643
Observations 26
ANOVA
df SS MS F SignF
Regression 2 15579777040 7789888520 25.432 0.0001
Residual 23 7045072780 306307512
Total 25 22624849820
Coeff Std-Error t-Stat P-value
Intercept 15800.0000 6038.2999 2.617 0.0154
Capital 0.1245 0.2045 0.609 0.5485
Wages 7.0762 1.4729 4.804. 0.0001
a. Referring to Table above, what fraction of the variability in sales is explained by spending on capital and wages?
A. 83.0%
B. 68.9%
C. 27.0%
D. 50.9%
b. Referring to Table above, when the microeconomist used a simple linear regression model with sales as the dependent variable and wages as the independent variable, she obtained an r2 value of 0.601. What additional percentage of the total variation of sales has been explained by including capital spending in the multiple regression?
A. 22.9%
B. 31.1%
C. 60.1%
D. 8.8%
c. Referring to Table above, what is the p-value for Capital?
A. 0.05
B. 0.01
C. 0.025
D. None of the above.
Referring to Table above, what are the predicted sales (in millions of dollars) for a company spending $500 million on capital and $200 million on wages?
A. 16,520.07
B. 17,277.49
C. 20,455.98
D. 15,800.00