# Probability & Statistics/distributions

Question
Dear Clyde,

I am studying CIA exam and we need to know to some degree about Statistics. I could not find a table in which are distribution types are compared. I mean how can we simplify which distribution is used when? say binomial means that and when sample size is less than 30 t-distribution comes to scene. When this is that poisson is on the scene. I wantto memorize their traits in a table. Can you tell me or just tell me website i can make a table.

The best website I can find that gives this type of information, after some searching, seems to be this one:

http://www.causeweb.org/repository/statjava/Distributions.html

It is important to note that sample-size is only one of many factors that can help you determine which distribution is appropriate. For example, the website says:

"The Binomial Distribution is used in finite sampling problems where each observation is one of two possible outcomes..."

"The Poisson Distribution is used for modeling rates of occurrence."

Sample size is mostly irrelevant here. The real question is what type of data you are modeling.
Questioner's Rating
 Rating(1-10) Knowledgeability = 10 Clarity of Response = 10 Politeness = 10 Comment thanks a lot.

Probability & Statistics

Volunteer

#### Clyde Oliver

##### Expertise

I can answer all questions up to, and including, graduate level mathematics. I do not have expertise in statistics (I can answer questions about the mathematical foundations of statistics). I am very much proficient in probability. I am not inclined to answer questions that appear to be homework, nor questions that are not meaningful or advanced in any way.

##### Experience

I am a PhD educated mathematician working in research at a major university.

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AMS

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Various research journals of mathematics. Various talks & presentations (some short, some long), about either interesting classical material or about research work.

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BA mathematics & physics, PhD mathematics from a top 20 US school.

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Various honors related to grades, various fellowships & scholarships, awards for contributions to mathematics and education at my schools, etc.

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In the past, and as my career progresses, I have worked and continue to work as an educator and mentor to students of varying age levels, skill levels, and educational levels.