A metalworking firm conducts an energy study using multiple regression methods. The dependent variable is y = energy consumption cost per day (in thousands of dollars), and the ­independent variables are x1 = tons of metal processed per day, x2 = average external temperature, x3 = rated wattage for machinery in use, and x4 = x1x2. The data are analyzed by Statistix. Selected output is shown here:
a. Write the estimated model.
b. Summarize the results of the various t tests.
c. Calculate a 95% confidence interval for the coefficient of METXTEMP.
d. What does the VIF column of the output indicate about collinearity problems?

  • CreatedNovember 21, 2015
  • Files Included
Post your question