Question: slit width 15cmdistance between the slits 6cm...

slit width = 1.5cm

Distance between the slits = 6cm

And I am given some data 

From the data, I need to plot a graph of meter reading versus angle, and find the angles at which you approximately see the maxima and minima. 

And then compare the graph with the minima and maxima that can be calculated from d sin(theta) = n lambda and d sin(theta) = (n +1/2) lambda.