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4 votes
5 answers
360 views

Expressions for moments of sample cumulants?

I sample $n$ points from standard normal and need the mean and variance of 3rd and 4th sample cumulants. @JimB suggested that variance of 4th sample cumulant is given by the expression below. This ...
2 votes
1 answer
136 views

Concatenation of Distributions

I would like to calculate mean, variance, ... of a concatenation of distributions (is this the correct technical term?). For an easy example I am trying to calculate the mean of a PoissonDistribution ...
0 votes
3 answers
350 views

How can I calculate the expected value of the sum of "n" i.i.d. variables with any distribution?

Particulary, I would like to find the expected value of the sum of $n$ variables distributed like ParetoDistribution[1,1.14]. For example, this works for the sum of two vars with Gamma distribution: <...
2 votes
1 answer
614 views

Compute symbolic Expectation of a summation

I am required to computed following Expectations : $E[\displaystyle\sum\limits_{i=1}^N \frac{X_{i}}{N}] = \bar{x}_{0}$ & $E[\displaystyle(\sum\limits_{i=1}^N \frac{X_{i}}{N})^2] = \frac{(N\bar{x}...
3 votes
2 answers
230 views

How do I check and justifiy a symbolic result returned by Mathematica?

Similar things have been asked previously (see https://academia.stackexchange.com/q/71536/4132 for instance), but I want to address the specific case in which a complex symbolic/analytical result has ...
6 votes
2 answers
245 views

MarginalDistribution with Symbolic range in ProbabilityDistribution

Given the following joint density: for 10 < x < 20, x/2 < y < x. To find the marginal density for X we do: ...
3 votes
1 answer
249 views

How to get a more compact form of this probability calculation?

Inspired by the probability calculation here, I am trying to solve a little general one: $$\mathbb{P} (\sum_{i=1}^{m-1} A_i + \sum_{i=1}^{m} S_i < L < \sum_{i=1}^{m} A_i + \sum_{i=1}^{m+1} S_i)$...
7 votes
1 answer
493 views

How to solve this probability symbolically or numerically?

I am trying to calculate the following probability $$\mathbb{P} \big(\sum_{i=1}^{m} (A_i + S_i) \le L < \sum_{i=1}^{m+1} (A_i + S_i) \big)$$ where, $$A_i \sim \exp(\lambda), \quad S_i \sim \exp(...