If my vaguely remembered math is working correctly, if you wanted to thin a whole bottle of LLA (4oz), the formula should be 4 oz of melted Johnson's Paste Wax, 4 oz of LLA, and .89 oz of mineral spirits.
As an aside, I've read that a really inexpensive substitute for LLA is available online (I know Ebay has it listed) It's made by White's lubes (IIRC) and is called XLOX. It's supposed to be the same stuff, maybe slightly lighter in color, but is available in quart sized containers, pretty cheap.
I'm not trying to undermine Lee, just putting the info out there. I'm a pretty faithful consumer of Lee products.. I like the way he does things. But, if you are lubing a LOT of boolits, this might be an option.