I am looking a two graphs, the first one is radiation vs $\frac{1}{x^2}$ (Inverse Square Law) and the second one is radiation vs $T^4$(Stefan-Boltzmann Law).
The equations of my inverse square graph is
$$y=412.32x+0.5541$$
and for my Stefan-Boltzmann graph it is
$$y=(2 \times 10^{-11})x+0.204$$
What I am trying to understand is, what does the slope and $y$-intercept of each line represent?
For the inverse square line, would the slope represent the baseline radiation, emitted from our source and the $y$-intercept is our ambient radiation?
For the Stefan-Boltzmann Law, I have seen repeatedly is that there are other equations derived from it, that involve the universal gravitational constant, is that what my slope is representing and the $y$-intercept is our error?