No problem. I've definitely seen a lot of baking articles that somehow try and make this simple concept unbelievably convoluted.

The only other thing to know is that 1 mL of water = 1 gram of water. Which means 170g of water == 170 mL of water (At STP... blah blah blah. It's not super important to hit exactly 70% you can hit 75% or 65% and you'll be fine. It's close enough to true).