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FRATQU33N

Member

Registered: 2016-08-21

Posts: 14

Understanding Various Probability Distibutions: Continuous RV's

Hello,

I was wandering if someone could help me understand under what circumstances the following continuous distributions are best to use. (eg, I would like to identify what the best distribution to use when given a scenario in a question)

Uniform

Gamma

Chi Squared

Exponential

Beta

Thank you so much for your time.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Understanding Various Probability Distibutions: Continuous RV's

Uniform - Pick between two values with all intervals of the same length on the distribution's support are equally probable.  Commonly referred to as the rectangular distribution, characterizes a random variable whose value is everywhere equally likely

Beta - Given s successes in n binomial experiments, one should estimate probability of a success as (s+1)/(n+2)

Look here for more explanation:

http://stats.stackexchange.com/question … stribution

Chi Squared: Best illustrated with a sample(no pun intended) problem.

A die is rolled 1200 times and the numbers that come up recorded.

1 comes up 216

2 comes up 204

3 comes up 186

4 comes up 180

5 comes up 210

6 comes up 204

Is the die fair?.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

FRATQU33N

Member

Registered: 2016-08-21

Posts: 14

Re: Understanding Various Probability Distibutions: Continuous RV's

Thank you!

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Understanding Various Probability Distibutions: Continuous RV's

You are welcome.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.