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2 votes
0 answers
81 views

When is $\sum Z_i \sim \sqrt{n} Z_i$?

If $X_i$ are independently and identically distributed $N(0,\sigma^2)$ then $Y=\sum X_i \sim N(0,n\sigma^2)$, i.e. $\sum X_i \sim \sqrt{n}X_i$. That raises two questions: Is a zero-mean normal ...
Henry's user avatar
  • 40.5k
0 votes
1 answer
114 views

How to apply Lyapunov CLT to data

I have a situation where I have around 30 classes of variables with different means and variances (though the means aren't too far from eachother; think 4-7) and that the distributions are right ...
Scott White's user avatar
2 votes
1 answer
34 views

Limiting distribution of infinite sparse sum

Let $N$ be a positive integer. I consider $N$ random variables $X_1^{(N)}, X_2^{(N)}, \dots, X_N^{(N)}$, all independent and identically distributed, each taking values $\pm 1$ with probabilities $p/(...
a06e's user avatar
  • 4,440
4 votes
2 answers
1k views

Does the sum of discrete uniforms converge to a discrete Gaussian?

Is there some analogous of the Central limit theorem for discrete uniforms and discrete normal distributions? To be more specific, let's say we have identical and independent random random variables $...
Hilder Vitor Lima Pereira's user avatar
7 votes
0 answers
1k views

Square roots of sums absolute values of i.i.d. random variables with zero mean

In an earlier question, I asked about the limiting distribution of the square root of the absolute value of the sum of $n$ i.i.d. random variables each with finite non-zero mean $\mu$ and variance $\...
Henry's user avatar
  • 40.5k
2 votes
1 answer
2k views

Sum of random variables without normalization approaches gaussian

The central limit theorem states that the limiting distribution of a centered and normalized sum of independent random variables with mean $\mu$ and finite variance $\sigma^2$ is Gaussian. $$ \frac{\...
fragapanagos's user avatar
13 votes
1 answer
5k views

Central Limit Theorem for square roots of sums of i.i.d. random variables

Intrigued by a question at math.stackexchange, and investigating it empirically, I am wondering about the following statement on the square-root of sums of i.i.d. random variables. Suppose $X_1, X_2, ...
Henry's user avatar
  • 40.5k
5 votes
2 answers
448 views

Sum of random variables without central limit theorem

I know that using central limit theorem we approximate sum of random variables into Gaussian distribution. Is the any other approximation method available for finding the probability distribution ...
upol94's user avatar
  • 301