Calculate the adjusted r² value (c). 

In a study of central city multiplex movie theaters, 15 theaters located in cities of similar size were selected. The theaters have the same number of screens and show a similar collection of movies. The table below gives the results of a multiple linear regression analysis intended to link monthly theater revenue per seat (in $) to two independent variables: number of parking spaces within two blocks of the theater (x₁) and proximity ( in feet) to the nearest subway, light rail, or trolley stop. (x₂).

Regression Statistics Multiple R R Square Adjusted R Square Standard Error Observations 15