how to figure levain % for dough hydration % question
What's the math or method for figuring out how to add a levain with a differnt hydration than the dough will be? So if I have a 130% hydrated levain and I want to make a dough of 70%, 75%, 80% - whatever it is - how do I figure out how to compensate? I'm just ignorant enough to not even know how to phrase the question so I sure hope someone can decipher this. The 130% and the 70%, 75% and 80% are just examples. It could also be a 50% levain to an 80% dough.