The following regression output was obtained from a study ofarchitectural firms. The dependent variable is the total amount offees in millions of dollars.
Predictor     | Coef | SE Coef      | T     | P | |
Constant | 7.987 | 2.967 | 2.69 | - | |
X1 | 0.12242 | 0.03121 | 3.92 | 0.0000 | |
X2 | -0.12166 | 0.05353 | -2.27 | 0.028 | |
X3 | -0.06281 | 0.03901 | -1.61 | 0.114 | |
X4 | 0.5235 | 0.1420 | 3.69 | 0.001 | |
X5 | -0.06472 | 0.03999 | -1.62 | 0.112 | |
| | | | | |
Analysis of Variance | | | | |
Source         | DF | SS    | MS     | F    | P |
Regression | 5 | 3710.00 | 742.00 | 12.89 | 0.000 |
Residual Error | 46 | 2647.38 | 57.55 | | |
Total | 51 | 6357.38 | | | |
X1 - # of architects employed by the company
X2 - # of engineers employed by the company
X3 - # of years involved with health care projects
X4 - # of states in which the firm operates
X5 - % of the firms work that is health care-related
- Write out the regression equation
- How large is the sample? How many independent variables arethere?
- Conduct a global test of hypothesis to see if any of the set ofregression coefficients could be different from 0. Use the .05significance level. What is your conclusion?
- Conduct a test of hypothesis for each independent variable. Usethe .05 significance level. Which variable would you considereliminating first?
- Outline a strategy for deleting independent variables in thiscas
