Want To Play A Statistics Game? (list the date of your b-day)

I saw this crazy shit on tv that I can't make sense of but it seemed real as hell and apparently there is math to back it up. I've always been real bad at math and want to see if this works and if so I need to know HOW.

If you want to play, these are the rules:

1) You need to list your b-day EXCLUDING the year. There is no need for the year.

2) Make a decision after you read this line, that you are either going to play or you are NOT going to play. I must repeat. If you want to play just list the month and year. Don't tell yourself, "I'm not gonna play", then you read the responses, see a matching date and change your mind to "force" a math. You're either in or your out so make up your mind right now so we can avoid any sampling or confirmation bias.

3) You should have your made up mind by now. Do NOT change it.

Now this is how it's suppose to work.

There are 365 days in a year. But apparently, if 30 people list their b-days (without the year) there's a >>70% chance we will see a match. So we have more than a 70% chance of getting a match before we get to page 2.

On tv they only had to ask 10 people to get matching dates. I want to see if we can also get a match under 30. And if we do I'd like some math wiz to explain why there's a 70% chance of a match with 30 dates when there are still 335 dates left in the year.

But let's place the game first! (if mods approve of course)

I'll start: 6-28

 

Assuming this is US format in terms of the date. 11-5.

 

In US form : 11 / 17

 

I'm in, why not. 7/7

 

Lets see where this goes BB,

3-28

(Assuming it is month/date)

 

ok im in

6-3

US format

 

9/27 (US format I see)

 

12-7

Let's see how this goes.

 

I'll stick with US format too (for you guys, personally I hate it )

15 - 08

 

Why not

2/8 (February 8th)

 

12-7..December 7th

 

US format is M/D

9/8 (Sept 8th) is mine

 

January 16th

But the number is right anyway, the chance quite high for us to find a match with 30 samples. Its simple, the first person has 365/365 chance to have unique date, for the second person its only 364/365 .. like that the 15th will only have 351 unique dates left with 15/365 = 4.1% chance to draw matching date, for the 30th its 8.2% chance to draw matching date

 

Well, looks like it took 11 posts to get here

 

11-10................10th November

 

12/25

christmas day

 

Nice job man I didn't even notice that!

11 freaking posts it took!

That's 1 more than it took on tv and I'm still confused as hell. This doesn't make any sense at all. Let me get to this next post...

Thanks a lot for trying to explain but your post just made me more confused.

You're saying "8.2%" chance of drawing at 30 which is incredibly low.

On TV they said it's a 70% chance.

What am I missing here? I will do the same math you did.

There are 365 days in a year. So the 2nd person who draws would have a 1/365 (1 divide by 365 X 100) or .27% chance of matching.

The 2nd person would have a 2/365 or .8% chance of drawing.

The 10th person would have a 10/365 or 2.7% chance

The 30th would have a 30/365 or 8.2% chance (like you said).

However, on tv they said that's not how the formula works. And they didn't bother to explain it cause they said most people wouldn't understand it. If the chance to draw at 30 is 8.2% that's incorrect based on the 70% figure I heard. So again, are there any mathematicians who know where that 70% chance is coming from?

This is confusing the shit out of me cause I've seen it done twice the 1st time it took 10 samples to match the 2nd it took 11.

THIS IS CRAZINESS.

 

Yes 8% is a freaking low chance if u only have 1 shot, but u see the 15th person gt like 4% chance to hit same date and from then on the chance will only improve and theres 15 more shots left.

4% is like a guaranteed hit out of 25 shots, and close to 60% at 15 shots. while its true the 30th person only got 8% chance to hit same number, the 29th person will have 8% ish too. its like 8.2% 7.9% 7.6% 7.3% 7% 6.7% 6.4% 6.1% for the last 8 shots, this last 8 alone gv u nearly 57.2% chance to hit the matching date.

 

27-12 (day 27 of december)