This assumes independent events. If someone picks 7 and you ask them for another random number, it is highly unlikely (certainly not 28.1%) that they will pick 7 again.
"Ask another person for a random number"
How to pick a random number from 1-10
51–60 of 183 posts
Re: How to pick a random number from 1-10
#52Or have them give the last digit of the age of their oldest living family member.
What about Benford's Law?
Re: How to pick a random number from 1-10
#53Re: How to pick a random number from 1-10
#54I usually just look at my watch and use the last digit of the seconds value. 0=10 reasonably random
Very easy to predict.
Re: How to pick a random number from 1-10
#55...or just add up the answers mod 10. This has the property that if even a single person answers uniformly at random, then the final number you compute will be uniformly random, regardless of how everyone else answers.
I'd love to see something written up about how quickly this converges, assuming the variables are i.i.d and distributed according to the distribution in the article.
Empirically, from running a quick script on the data in the article, it seems like you only need to sample 5 numbers to get a distribution that looks uniform using this "sum mod 10" method.
Re: How to pick a random number from 1-10
#56> The easy thing to do is to ask someone “Hey, pick a random number from 1 to 10!”. The person replies “7!”.
Seven factorial is way bigger than 10. Just kidding, sorry.
But what I was actually going to say was, when I read the title of the post, before clicking through, I decided to think of a number myself and I chose the number seven. So it was fun to see that same number in the article.
10% chance in theory and in reality it’s about 25% likely for someone to pick the specific number I did. If only the odds in the lottery were this good.
Why, by the way, is it that seven is so popular?
Re: How to pick a random number from 1-10
#57There's no need to solve the distribution balancing problem with linear programming. You can just use a greedy algorithm where you repeatedly give probability mass from numbers with more than 10% to numbers with less.
Re: How to pick a random number from 1-10
#58This can be generalized to having any distribution, simulating a die:
Re: How to pick a random number from 1-10
#59...or just add up the answers mod 10. This has the property that if even a single person answers uniformly at random, then the final number you compute will be uniformly random, regardless of how everyone else answers.
> This has the property that if even a single person answers uniformly at random
Has any human ever proven they're capable of this? Generating truly random sequences is more or less impossible for humans AFAIK. (E.g., see https://news.ycombinator.com/item?id=19336754 which challenges you to do just that. Spoiler: you will probably fail miserably.)
It's an interesting idea, but in practice I think relying on the assumption that "even" one person is truly answering randomly (let alone uniformly at random) is a non-starter. But perhaps if there are enough people, the resulting sequence blends enough entropy together to get something that looks almost like a uniform random variable anyway? It would be interesting to test empirically.
Re: How to pick a random number from 1-10
#60> The easy thing to do is to ask someone “Hey, pick a random number from 1 to 10!”. The person replies “7!”. Seven factorial is way bigger than 10. Just kidding, sorry. But what I was actually going to say was, when I read the title of the post, before clicking through, I decided to think of a number myself and I chose the number seven. So it was fun to see that same number in the article. 10% chance in theory and in…
It's large and prime, so it feels less "round".