so raschemmel.. if I am understanding your description of the solution correctly.. I have drawn this circuit diagram of how I would have things wired up. Is this correct?

In your calculations... Rtotal = Vin / Iload

Can you explain this? Where is Iload? is this the current through R1? Did you pick 1mA for any specific reason?

So using the resistor values you have provided, when Vin = 130vdc, then Vout =4vdc. Is this how I can calculate what the Vout will be when Vin = 100vdc?

R2 / Rtotal = Vout / Vtotal

4000 / 130 000 = Vout / 100v

Vout = 3.077vdc.

So when Vin = 100vdc, then the arduino will get a 3.077vdc signal at the analog input pin. Correct?

For everyone else following this thread.. The source voltage is coming from an induction motor converted to a permanent magnet generator. The voltage produced by this generator fluctuates depending on the speed that the generator is turning. I need the constant 36vdc to power LED lighting. By measuring the supply voltage (100 - 130vdc), I will be able to program the arduino board to turn a power mosfet on and off at the correct rate in order to produce the 36vdc needed for the LEDs. If the supply is at 115v, then the mosfet will need to be turned on (36/115) x 100 % of the time, or 31.3% of the time. If the supply is 130v, then the mosfet will need to be turned on (36/130) x 100 %, or 27.7% of the time. Hope this makes sense to everyone.