I was investigating the impact of slit distance on the fringe seperation using Young's double slit setup, and produced the following graphs. I need to analyse the experimental uncertainty, however I don't understand what the expected equation of the graph is supposed to be? So, in the form of y= mx+c, what value would the gradient represent (i.e: in a photoelectric setup, the gradient represents Planck's constant), and how would I find this value? For reference, these are my graph equations (one is linearised using 1/slit distance and one is exponential).

Impact of Slit Distance on the Average Distance Between Peaks (Fringe Seperation) Impact of 1/ slit distance on the average distance between peaks (fringe seperation) 9.000 9.000 8.000 8:000 7.000 7:000 6.000 y = 12.947e-41.60 y =0.3602x + 0.3012 6:000 Average Distance between slits (mm) 5.000 4.000 5.000 Average distance between slits (mm) 3.000 4:000 2.000 3.000 1000 0.000 2.000 0.045 0.055 0.065 0.075 0.085 0.095 0.105 0.115 0.125 1.000 Slit distance (mm) 0.000 O in 1/ Slit Distance (1/mm)