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1 vote
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86 views

How to find $\mathbb{E} \left[\frac{\bar{\mu}}{\bar{\sigma}^2}\right]$?

I asked the same question on math stacks: MathStacks:, and some user suggest to ask it here for better insight. So this question has found interest in many research problems, but there have been no ...
coolname11's user avatar
1 vote
0 answers
79 views

Bounds on distance between two independently variables drawn from the same distribution

Suppose $X_1$ and $X_2$ are iid from an arbitrary distribution with variance $\sigma^2$. How can we derive an upper bound for: $$P(|X_1-X_2|\ge\delta)$$ One simple idea is Chebyshev's Inequality, ...
Claucisco's user avatar
1 vote
2 answers
545 views

Two distributions, same mean, different variance: Stochastic dominance for deviation from mean?

Say you have two (bounded) random variables, $X$ and $Y$, on the same discrete probability space, such that $E(X)=E(Y)$ but $Var(X) < Var(Y)$. Do I know that, for any $k \geq 0$, $$ \text{Prob}(|X-...
Paul's user avatar
  • 33
2 votes
0 answers
130 views

Existence of estimator that reaches Cramer-Rao bound

There is a well known classical result called Cramer-Rao bound: https://en.wikipedia.org/wiki/Cram%C3%A9r%E2%80%93Rao_bound Particularly, it is a lower bound for a variance of any unbiased estimate. ...
Byobe's user avatar
  • 121
4 votes
0 answers
101 views

Index of dispersion with approximate distribution

I have an unknown discrete probability distribution $D$ ($D$ is a probability mass function), defined on an interval $[a,b]$ ($a>0$) and an estimation $\hat{D}$ such that, for all $t\in[a,b]$, $$(...
Matteo's user avatar
  • 213