All Questions
Tagged with birthday probability-distributions
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Number of date collisions in birthday problem
If I generate uniform random integers from 1 to K and count how many unique numbers I get $n_\mathrm{unique}$, I empirically obtain:
the mean is: $\frac{2K}{\pi}$
the variance is $\frac{K}{\pi^{2}}$.
...
- 365
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How many days with birthdays are in a classroom?
Assumption:
I am a teacher of a classroom with n students. And every time there is one or more birthdays in a day, I will buy only a cake.
Question:
How many cakes do I have to buy on average every ...
4
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Probability distribution for birthday paradox
In Wikipedia we read
In an alternative formulation of the birthday problem, one asks the average number of people required to find a pair with the same birthday. If we consider the probability ...
- 523
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Probability distribution for collisions / birthday problem
Let's say I have a source of randomly produced values from a range $M$. I want to test if the source is a uniform distribution by examining a sample sequence of $n$ values $m_1, m_2,\dots,m_n$. ...
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Distribution for count of unique elements
Consider the selection, with replacement, of $N$ elements uniformly at random from $\{1, 2,\dots, M\}$. From the selected elements, count the number of unique elements.
Does the distribution of this ...
- 175
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Minimising the probability of two people having the same birthday?
I was asked a particularly weird question at an interview today:
Suppose Alice and Bob live on a universe in which a year has $k$ days. What probability distribution of birthdays would you choose ...
- 2,238
2
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1
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The birthday-cake problem: a variation on the birthday problem
Suppose we randomly select 100 people and record each of their birthdays. (Assume a year of 365 days, and an equal chance of being born on any of them.) Suppose further that over the course of a year, ...
- 153
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Mean number of unique choices given n people choosing randomly from a set of N elements
My question is similar to the birthday problem, but I can't seem to find a simple solution. The question (in a general form) is that, given a set of $n$ people who each choose elements from a set of $...
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Why birthday distribution is not uniform. [closed]
I was reading about birthday problem and I found a statement that real-life birthday distributions are not uniform since not all dates are equally likely (last line ...
- 2,138
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871
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Determine the accuracy of Poisson approximation to birthday problem
I'm currently doing an exploration of the Birthday Problem, and noticed that the formula given to calculate the probability for $m$ people in a room is:
$$1-\frac{365!}{365^m (365-m)!}$$
And this ...
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