Right away this looks like something related math, what with the [█, █) and ~ ███(█).
I'm trying to spend a little less time on these, so let me try a few things right away:
mathematics gets 0 but function gets 16.
A bunch of other words get me very little (equation gets 3, but linear, cosine, and algebra get 0). Entering x to fill blanks all those equations and definitions helps at least confirm I'm on the right track.
But my limited knowledge of mathematics is showing, here, and all my next guesses (axis, derives, quadratic, square, number, value, and sum) yield very little.
But then I hit on statistics, and that seems promising.
I try ratio (spelling it correctly for a change, after paying close attention so I don't mistype radio again), but that's no good, but then theory helps a little (I was thinking game theory even though I knew that probably didn't have anything to do with the article) - and that got me to probability for the phrase probability theory (a logical connection to statistics - which doesn't have a lot of hits, but appears in the first sentence).
So now I'm pretty well stumped - I'm on the right track, but I bet I lack the domain knowledge to actually figure this out.
HAH! And once again, I guess a word that I figure will at most give me a few hits, maybe nudge me in the right direction, but turns out to actually be part of the topic: distribution.
And once again, I'm not sure I can figure out the missing title word. It's not random; too long.
Oh, but it starts with a vowel:
"The probability ███████ function (███) of an ███████████ distribution"
But, after wracking my brain, I concluded that I was not going to be able to solve this one, so I cheated - I went to the list of Level 4 articles, clicked into Math, and searched for Distribution - and seeing one that started with a vowel, I entered exponential , and that unlocked it for me.
So, yeah, statistics is something I've tried to dive into many times and never gotten very far. I should learn more about this stuff.
So - on the right track, but ultimately stumped, and had to cheat to get it.
Better luck tomorrow, maybe.