Why doesn't static friction vs normal force pass through the origin?

[SwAnK]

hey I did this experiment where I dragged a mass by a scale until it moved to find the static friction. Then weight was added to the mass and the process reapeated. My question when graphed and the mass or Fn on the x-axis and the applied force or Fs on the y-axis should it not plot a straight line through 0,0, which owuld be the coeffiecent of static friction?? I am just wanting to know because either i messed up the graph or got messed up results during the experiment.
thanx for your time

 

[Q_Goest]

Per the theory that static frictional force equals normal force times coefficient of friction, yes the line graphed should cross 0,0. The line should be straight and the slope indicates the coefficient (dy/dx).