W   D
120 100
150 80
200 60
300 40
400 30

The graph looks like this, connected with line segments

Note: [I did not mark off the units on the horizontal and
vertical axes, below the points and to the left of the
points, but you should do that on your work-sheet]



Or preferably, connected with a smooth curve, like this



Since the graph goes down as we move to the right, we suspect
that Distance varies INVERSELY as Weight.  So we write the
inverse proportional equation

 

We pick any data point to substitute.  May as well pick
the W=120 and D=100

 

 

So the equation is

  

Now plug in your own weight, and find the point that would
balance your seesaw.  For instance, if you weigh 130, you
would substitute W = 130, and get

 

  approximately,
which would be your distance, and you would mark your 
point, representing your weight and distance,
(W,D) or (130,90.3), say, in red, like this:



Edwin