# Questions tagged [distributions]

A distribution is a mathematical description of probabilities or frequencies.

9,640 questions
Filter by
Sorted by
Tagged with
18 views

### Is there a way to statistically compare the standard deviation of two distributions?

Suppose that a set of 100 items are responded to under two different conditions. Instead of comparing the means, is it possible to compare other things about the distribution of responses, for ...
• 2,661
31 views

### How to show that many functions (a hundred, a thousand) have the same shape an distribution of values over an interval?

I have functions that on iterval [0,1] all seem to look like this: i.e. they have a zero around 0.4 +ve derivative from zero to 0.4 and around zero or slightly negative derivative up to 1. I plan to ...
226 views

### Estimating mean and SD given the median and IQR values

it is possible to estimate mean and SD given the median and IQR? I am involved in a meta-analysis where some trials show outcomes as mean and standard deviation but most show median and inter-quantile ...
• 185
12 views

### Distribution to describe size of population with random exponential growth

Is there a distribution family that describes the size of a population experiencing random exponential growth (either discrete or continuous)? For context, I am trying to computationally model a ...
58 views

### Exercise on finding probability density function

Let $Y_1$ and $Y_2$ by independent and uniformly distributed over the interval (0, 1). Find the probability density for $U = Y_1/Y_2$: Solution: $F_U(u) = P(U \le u) = P(Y_1/Y_2 \le u)$. Looking at ...
• 121
619 views

### Can a non-symmetrical distribution have the same areas under the PDF in the two sides around the mean?

I was thinking about symmetrical vs. non-symmetrical distributions and I found myself stuck in a thought that I had never thought before. We know that symmetrical distributions like Normal, Laplace, ...
• 33
40 views

• 9,381
1 vote
32 views

### Conditional expectation of a multivariate normal distribution

Let $(X,Y,Z)$ have a multivariate normal distribution: \begin{align} (X, Y, Z) \sim N\left(\begin{pmatrix} 0 \\ 0 \\ 0 \end{pmatrix}, \begin{pmatrix} 1 & \rho_{xy} & \rho_{xz} \\ \rho_{xy} &...
• 282
13 views

### By means of what distribution can I match the first n moments for arbitrary (i e. any) values of those moments?

Suppose I have the first n moments from some data set, either raw, centered or scaled, (or cumulants instead) whichever is more convenient for matching. Is there a continuous, continuously ...
• 3,157
1 vote
28 views

### A set of values ​from a discrete uniform distribution is scaled down by the same factor

Use MATLAB's randi function to generate a set of values ​​that conform to discrete uniform distribution, such as {0,1,2,3,4,5}. If this set of values ​​is divided by an integer 10 at the same time, ...
• 107
326 views

### Can a finite decimal number be a discrete variable?

If I have an array {0.1, 0.2, 0.3, 0.4, 0.5}, is this a discrete array? Are the values in it discrete values? (I have this doubt because many materials show that discrete values are usually integers) ...
• 107
1 vote
26 views

### Choosing a unique visitor on the fly

I've been thinking of this as the "Prize of the Week" problem. Suppose you run a shop, and want to give out a prize once a week to someone making a randomly-selected purchase. You give out ...
• 111
15 views

### What is the probability of condition rating 5 following a given condition rating?

I have an asset management system in which assets are given a condition rating from 1 (good) to 5 (bad). Assets are inspected and given a rating every year; new assets start with condition rating 1 ...
• 125
26 views

### Predicting if individual has a trait based on their previous locations (distribution of trait at locations is known)

I have been thinking about a problem and I was wondering if anyone has the right name/method/textbook of how this problem should be approached, or if they would be willing to help with finding a ...
1 vote
18 views

### Difference between 3 (not PDF/CDF) distribuitions [closed]

I have multiple (>20) variables that describe 3 different objects, and I wanted to see which variables differ the most across these 3 objects. I was thinking about using KL-divergence/KS-test/...
(This comes from a Facebook post, reference at the end) "Everybody knows" that the function $x \mapsto \exp\left(-1/x^2 \right)$ is infinitely differentiable, but not (real) analytic, ...