The following regression output was obtained from a study of architectural firms. The dependent variable is the total amount of fees in millions of dollars.

x1 is the number of architects employed by the company.
x2 is the number of engineers employed by the company.
x3 is the number of years involved with health care projects.
x4 is the number of states in which the firm operates.
x5 is the percent of the firm’s work that is health care–related.
a. Write out the regression equation.
b. How large is the sample? How many independent variables are there?
c. Conduct a global test of hypothesis to see if any of the set of regression coefficients could be different from 0. Use the .05 significance level. What is your conclusion?
d. Conduct a test of hypothesis for each independent variable. Use the .05 significance level. Which variable would you consider eliminating first?
e. Outline a strategy for deleting independent variables in thiscase.