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by grayclhn 1546 days ago
To be super pedantic, for one million ops it's closer to a 63% chance every day:

Pr[something happens across 1_000_000 events]

= 1 - Pr[nothing happens across 1_000_000 events]

= 1 - Pr[nothing happens once]^1_000_000 ## assuming independence

= 1 - (1 - Pr[something happens once])^1_000_000

= 1 - (1 - 1/1_000_000)^1_000_000

≈ 1 - 0.378

= 0.632

It's still below 99% for 4 million ops.

1 comments

> for one million ops

Okay, but they said millions.

> It's still below 99% for 4 million ops.

I find this misleading, because it's... 98%.

Which completely undermines your argument. If something happens 98% of days, it's fine to call that "every day".

Dude, it was meant to be mildly educational, not an "argument."
Then present it as a fun fact rather than as a correction?

And I'm not trying to be mean but I think the way you phrased your last line is accidentally anti-educational. Your last line treats 1 million ops and 4 million ops as nearly equivalent, when the truth is that 1 million ops is far from "every day" while 4 million ops can easily be called "every day".

And if you dislike the word "argument" pretend I said "point"? I think you're reading connotations into that word that I didn't intend.

And yet... here you are, having applied that same mathematical principle to calculate the probability of observing a one-in-a-million event at least once in 4mil independent trials. That's probably something you already knew how to do, but if not, it's a pretty educational moment. ;)

ps — "to be pedantic" means "fun fact" but sarcastically.

The bulk of your post was educational, but it was misleadingly shown as an answer to both "million" and "millions", when those two scenarios actually have very different answers.

> ps — "to be pedantic" means "fun fact" but sarcastically.

It means that, but also sets it up as a correction. But "millions" being "every day" was right all along.