Sum of discrete uniform random variables

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SUMMARY

The discussion focuses on finding the distribution of the infinite sum of independent and identically distributed (iid) uniform discrete random variables, specifically ##X_k##, which are uniformly distributed over the set ##\{0,...,9\}##. The sum is expressed as ##Y = \sum_{k=1}^{\infty} \frac{X_k}{10^k}##, representing a random number between 0 and 1 with decimal digits that are iid uniformly distributed. Participants attempted various methods, including decomposition into Bernoulli trials and characteristic functions, but encountered difficulties in deriving a clean solution. The key insight is recognizing that the resulting random number's distribution is uniform over the interval [0, 1].

PREREQUISITES
  • Understanding of discrete uniform distributions
  • Familiarity with the concept of independent and identically distributed (iid) random variables
  • Knowledge of characteristic functions in probability theory
  • Basic principles of limit theorems in statistics
NEXT STEPS
  • Study the properties of uniform distributions on the interval [0, 1]
  • Learn about the Central Limit Theorem and its applications in probability
  • Explore the concept of characteristic functions and their role in distribution analysis
  • Investigate the implications of iid random variables in statistical modeling
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Students and researchers in probability theory, statisticians working with random variables, and anyone interested in the properties of uniform distributions and their applications in mathematical modeling.

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Homework Statement


Let ##X_k## be iid uniform discrete on ##\{0,...,9\}##. Find the distribution of ##\sum\limits_{k=1}^{\infty} \frac{X_k}{10^k}##

Homework Equations


The Attempt at a Solution


I've tried a lot of things, I've tried decomposing ##X_k## into 10 bernoulli trials, I've tried using some form of central limit theorem. I've tried calculating the characteristic functions, then taking the limit and I get something really ugly. Any hints? I feel like there is some limit theorem I don't know.
 
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avidaware said:

Homework Statement


Let ##X_k## be iid uniform discrete on ##\{0,...,9\}##. Find the distribution of ##\sum\limits_{k=1}^{\infty} \frac{X_k}{10^k}##


Homework Equations





The Attempt at a Solution


I've tried a lot of things, I've tried decomposing ##X_k## into 10 bernoulli trials, I've tried using some form of central limit theorem. I've tried calculating the characteristic functions, then taking the limit and I get something really ugly. Any hints? I feel like there is some limit theorem I don't know.

If you observe ##Y = \sum_{k=1}^{\infty} X_k / 10^k## you will see a random number between 0 and 1 and whose decimal digits are iid uniformly distributed in 0--9. How do you think such a number will be distributed?
 
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