Advanced Enhancement Scrolls

I remember someone asking this question in another thread, but the search function couldn't find it.

Okay, so here is the question. If I used 3 regular enhancement scrolls on an item and then used an advanced one, will the success rate be 100% or 50%?

Believe the success rate is determined by the amount of stars. So wouldn't it be 70%?

Don't quote me on that though. Better to get more exp people to answer.

I believe it's 70% since it goes by the number of stars on the item.

Edit: Dang