Probability contours for the power law normalization r ₀ and slope γ of the total RASS-AGN sample (black, central contour), low L _X RASS-AGN sample (gray, left contour), and high L _X RASS-AGN sample (gray, right contour). The solid contours represent the 1σ confidence intervals (68.3%) for a one-parameter fit based on a correlated χ ² = χ ² _min + 1.0 (Equation (12)), while the dotted lines illustrate the corresponding intervals for a two-parameter fit (1σ, correlated χ ² = χ ² _min + 2.3).