Interference - Finding distance between slits

[mattbonner]

Homework Statement

A laser is shone through a set of slits and onto a screen.
I have a Δy vs. L graph plotted, where Δy is the spacing between successive nodes, and L is the distance from the slits to the screen. I'm supposed to find the spacing between the center of the slits. The value of λ is given.

Homework Equations

Δy = λL/D
y is the spacing between successive nodes
L is the distance from the slits to the screen
D is the spacing between the center of the slits

The Attempt at a Solution

I have the slope, but I don't know where to go from there...
I'm thinking that the slope will be equal to λ/D? and if I know λ, then I can calculate D. Not sure if this is the right way to go though.

 

[Redbelly98]

I'm thinking that the slope will be equal to λ/D? and if I know λ, then I can calculate D.

Yes, that's right.