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Upper Bound for Moments for Product of Sample Means

I have a question about the upper bound of the following moment. Suppose that $(A_1, e_1),\ldots, (A_n, e_n)$ are i.i.d. with $E(e_i)=0$. I am wondering if we have the bound $$E\bigg(\bigg\|\frac{\...
beginner's user avatar
1 vote
1 answer
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Variance of sum of deviations

Suppose I have an i.i.d. sample $\{X_i\}_{i=1}^M$ for some positive integer $M$, and suppose that $X_i \sim X$ for some random variable $X$ with finite variance. Then, denote by $$ E_M = \frac1M\sum_{...
G. Gare's user avatar
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$\max_{\{X_N\}}{\frac{\mu^2(X_N)}{\mu^2(X_N)+\sigma^2(X_N)}}$ for $X_N=\{x_1,...,x_n\},x_i\in \mathbb{N}^+,\exists(i,j):x_i\neq x_j$

Short version of the question Consider \begin{equation} g(X_n)=\frac{\mu^2(X_N)}{\mu^2(X_N)+\sigma^2(X_N)}\\ X_N=\{x_1,x_2,...,x_n\},n>1,\forall i:x_i\in \mathbb{N}^+,\exists(i,j):x_i\neq x_j \end{...
hossayni's user avatar
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