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0 votes
0 answers
92 views

How to add noise into a standard distribution without increasing its variance?

Suppose I have a standard distribution dataset X with a mean 0 and std 1. Now I want to create slight variations of this data by injecting some noise. I could make ...
Anonymous's user avatar
  • 181
-1 votes
1 answer
200 views

Consistency when we want to find the distribution of sum of random variables following each one a distribution

I want to clarify a point that disturbs me among different cases. I am interested in formulate correctly in a general case when we know the distribution of different random variables and we want to ...
user avatar
1 vote
1 answer
266 views

2 approaches for Monte-Carlo : weighted sum of $\chi^2$ distribution and Moschopoulos distribution with Gamma distribution

If I take as definition of $a_{lm}$ following a normal distribution with mean equal to zero and $C_\ell=\langle a_{lm}^2 \rangle=\text{Var}(a_{lm})$, and if I have a sum of $\chi^2$, can I write the 2 ...
user avatar
1 vote
1 answer
236 views

Expectation of Maximum and Minimum of Partial Sums of Normal Random Variables

Peggy Strait, 1974, Pacific Journal of Mathematics ON THE MAXIMUM AND MINIMUM OF PARTIAL SUMS OF RANDOM VARIABLES Gives a nice result (4.3) and (4.4) in terms of "standard normal random variables&...
Andrei Pozolotin's user avatar
1 vote
1 answer
45 views

Sum of estimated costs for uncertain events

I have a number of possible events $e$ with a probability $p_e$ of the event occuring and a cost estimate should the event occur (if it doesn't occur the cost is 0). The probability for each event is ...
nononono's user avatar
3 votes
1 answer
140 views

What is the expectation of $\left\langle (n \bar{y})^4 \right\rangle$, if $y_i \sim \mathcal{N}(\mu,\sigma^2)$?

Let $y_i \sim \mathcal{N}(\mu,\sigma^2), \; i = 1,\ldots,n$ and $\bar{y} = \frac{1}{n} \sum_{i=1}^n y_i$, such that $n \bar{y} = y_1 + \ldots + y_n$. Then, we want to know what the expectation of $(n \...
Joram Soch's user avatar
0 votes
0 answers
299 views

Sum of IID normal variables with index following Poisson distribution

$X_1, X_2,\ldots$ are a sequence of independent normal random variables with mean 1 and variance 1. Calculate the variance of $X_1+X_2+X_3+\ldots+X_{N+1}$ where $N$ follows Poisson distribution with ...
Tabludif's user avatar
1 vote
1 answer
119 views

How to evaluate Probability of Y?

Hi all, It's my first undergraduate statistics module as a business major and I've encountered some difficulties in computing the response to the question. I have several queries below: Would Y have ...
TropicalMagic's user avatar
1 vote
1 answer
953 views

Distribution sum of correlated normal variables squared

I'm trying to deduce which distribution my data follows and how to estimate the parameters. I have four random variables $X_i \sim N(\mu_i,\sigma_i^2)$ where the means and variances are all different. ...
PhPanda's user avatar
  • 113
5 votes
1 answer
578 views

How do I find the conditional distribution of a normal r. v. z, given that I know the sum of z and another normal r. v. x is greater than some value?

Suppose I have two independent normal random variables, $X$ and $Z$ with $\mu_x$, $\sigma^2_x$ and $\mu_z$, $\sigma^2_z$. Suppose I also know that $x+z\geq y$. How do I find the conditional ...
thagomizer's user avatar
2 votes
2 answers
1k views

Why is the sum of all the elements in a Gaussian-distributed list with zero mean not zero?

If I generate a list of elements from a Gaussian distribution with zero mean using Python List = np.random.normal(0, 1, 500) my intuition (why is obviously wrong) ...
Dennis's user avatar
  • 145
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
2 votes
2 answers
147 views

Inferring random variables from their sum

Suppose I have a large set of receipts that list the items I bought, but only list the total cost. One day I might have bought Milk, Butter, and Eggs. A different day I might have bought Bread, Milk,...
Ben's user avatar
  • 473
5 votes
2 answers
621 views

Deconvolution of the sum of three gaussian distributions

Consider the sum of three normal random variables: $ R_{i,j}=A_{i}+B_{j}+C_{i,j}\, $ where $ A_{i}∼N(μ_{A},σ_{A}) $ , $ B_{j}∼N(μ_{B},σ_{B}) $ and $ C_{i,j}∼N(μ_{C},σ_{C}) $ . Assuming $A$, $B$ ...
Rick's user avatar
  • 53
0 votes
1 answer
117 views

Summation of two Gaussian distributed data with different coefficient of mean and variance

I need some help on Gaussian distribution. i have two dataset, both are identical and independent distributed, but having mean as 2μ_1 and μ_2, same scenario for the variance. How can I add them? ...
Tania islam's user avatar

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