# distributions's questions - English 1answer

5.708 distributions questions.

### Find out which characteristics to choose, based on the frequency measurement of characteristics of similar items

1 answers, 5 views distributions forecasting frequency
I have this statistics oriented question and I need some input on the approach. There is a new product introduced, a contact lence that has seleral ranges of attributes (powers) from which the users ...

### CDF and PDF of radius of a unit disk

0 answers, 5 views distributions pdf cdf
Let X and Y be uniformly distributed on a unit disk such that $x^2 + y^2 + 2 \leq 1$ Let $R = \sqrt{X^2 + Y^2}$. Find the CDF and PDF of $R$. I start by writing $P(X^2 + Y^2 \leq -1)$, but this ...

### which distribution should be used in this question?

A basketball player succeeds in making a basket three tries out of four. How many times must he try for a basket in order to have greater than 0.99 probability of making at least one basket? In this ...

### 3 Find the pdf of $\frac{Z_1}{\sqrt{(Z_1^2+Z_2^2)/2}}$ where $Z_1,Z_2$ are i.i.d standard normal

1 answers, 55 views distributions t-distribution
Given $Z_1, Z_2$ are i.i.d standard normal random variables. Let $$V:=\frac{Z_1}{\sqrt{(Z_1^2+Z_2^2)/2}}$$ Derive the pdf of $V$. The numerator and denominator of $V$ are dependent, so the square ...

### How to find joint distribution of $\min(U_0,U_1)$ and $\min(U_1,U_2)$ where $(U_0,U_1,U_2)$ are i.i.d Uniform?

1 answers, 33 views probability self-study distributions
I have this homework question where there are 3 random variables $(U_0,U_1,U_2)$ which are independent and uniform in the interval $[-1,1]$. I have two other random variables $(X,Y)$ defined as ...

### 1 Is this zero inflated negative binomial distribution?

I have this vector data and I am trying to find distribution that this data fits. ...

### Difference between several/Multivariate Random Variables (RVs) & a Sequence of RVs?

What is the difference between several/Multivariate Random Variables (RVs) & a Sequence of RVs? Example: Picking a student from class and noting his/her height and weight is several RVs (...

### 3 Properties of normal distribution

2 answers, 53 views distributions normal-distribution
I've been trying to prove the following: $$\phi'(x)(1-\Phi(x))+2\phi(x)^2>0$$ where $\phi$ is the standard Normal pdf and $\Phi$ its cdf. I've tried many simulations and I believe it's true in ...

### What is the probibility of a 1,1 distribution of the oponents hands in Bridge. [on hold]

0 answers, 23 views probability distributions games
What is the probability of a 1,1 distribution in Bridge when there are 2 cards outstanding? I understand there are 4 possible outcomes, for example Kx and 0, 0 and Kx, K and x, x and K. That is, 2 ...

### 11 Is it possible that two Random Variables from the same distribution family have the same expectation and variance, but different higher moments?

I was thinking about the meaning of location-scale family. My understanding is that for every $X$ member of a location scale family with parameters $a$ location and $b$ scale, then the distribution of ...

### How to measure product adoption across different zones

I am very new to this subject, but i've tried searching other questions and haven't found what i need. I'm working on an application that will be promoted in physical meetings. Lets say, for example, ...