You're supposed to weigh yourself fully dressed to ride, and the bike fully equipped to ride. I weigh 145 lb. and my bike weighs 20.5 lb, but when dressed to ride with water bottle etc. on the bike and using a 40%/60% split between front and rear wheels, the chart says I should use 110 psi in back and 75 in front for 700cx23 tires.

Ideally you're supposed to actually find out what you and your bike weigh on a scale by putting the scale under each wheel (and a support under the other to keep everything level) and then look up the pressure on the chart.

If I remember correctly, the article mentions that if the recommended pressure is too low, use a narrower tire; if too high, use a wider tire.

I converted the chart into a calculator that you plug numbers into and it tells you the matching psi values from the chart. It also offers the numbers from Michelin Bicycle Tires weight-based chart for 700c tires as an alternative.