30% is specific, as if it's the result of a calculation in a spreadsheet. But with something like getting a promotion, how would you calculate that so specifica

30% is specific, as if it's the result of a calculation in a spreadsheet. But with something like getting a promotion, how would you calculate that so specifically? You can't. That's why people don't take it seriously. "Not very likely" is a rough estimate, like "probably not", or "less than 30% likely". It's a lot more believable that with the information you know, you're able to predict with that certainty.