The last one occurs once? No — we have only four positions. If one occurs twice, two others once, that’s 2+1+1 = 4, so the fourth is covered. So the fourth outcome (the unused one) doesn’t need to be chosen — it’s determined.

Mon, 20 Apr 2026 03:55:51 +0000

Understanding the Hidden Probability: Why the Fourth Unused Outcome Isn’t Really Missing — It’s Determined When analyzing probability distributions with exactly four possible outcomes, a common misconception arises: If one outcome occurs twice and the others once each, how is the fourth outcome counted? And is it truly “missing”? The answer is clear: no outcome is truly missing — the fourth is determined and logically following from the structure. ### Breaking Down the Scenario Imagine a scenario where there are four potential outcomes — let’s call them A, B, C, and D. In one trial, outcomes repeat or combine in such a way that: