Bigelow Roofing is developing a model to help its estimators bid on new roofing jobs. Below is output from a regression analysis attempting to link the dependent variable y (labor cost) to independent variables x₁ (area of the roof), x₂ (pitch of the roof), and x₃ (number of special areas such as porches, skylights, etc.) using a sample of seven recent jobs. Partial results from the analysis are shown below. Compute the value of the adjusted r 2 and explain what it represents.

Regression Statistics Multiple R R Square Adjusted R Square Standard Error Observations 0.961 0.923 12.315 ANOVA df Regression Error (Residual) Total 5487.91 454.95 5942.86