An astrophysics student investigates a heated, spherical blackbody radiator of surface area \(A\). The student measures the peak emission wavelength \(\lambda_{\text{max}}\) of the spectrum and the total radiated power \(P\) as the temperature of the radiator is varied. The system is described by Wien's displacement law \(\lambda_{\text{max}} T = b\) and the Stefan-Boltzmann law \(P = \sigma A T^4\), where \(b\) is Wien's constant and \(\sigma\) is the Stefan-Boltzmann constant. To produce a linear graph with a constant slope, which quantities should be plotted on the vertical and horizontal axes, and what is the expression for the slope of the line?