## Distributions

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dipti5ece
Contributor
Posts: 134
Joined: Tue Sep 09, 2014 8:31 am

### Distributions

What are the different type of distributions that we need to know for exam.

Any detailing? Continuous, Normal, lognormal,uniform,discrete etc...
signor_rk
Contributor
Posts: 182
Joined: Wed Jun 18, 2014 3:47 pm

### Re: Distributions

hi Dipti ,

Here is a link related to this topic (Courtesy : Deep Fried Brain ). Please have a look :
http://www.deepfriedbrainproject.com/20 ... jects.html

Thanks
Regards ,

Ranjit
dipti5ece
Contributor
Posts: 134
Joined: Tue Sep 09, 2014 8:31 am

### Re: Distributions

Thankyou Ranjit!!!
signor_rk
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Posts: 182
Joined: Wed Jun 18, 2014 3:47 pm

### Re: Distributions

Most welcome ...
Regards ,

Ranjit
coolpmp69
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Posts: 282
Joined: Mon Nov 17, 2014 8:55 pm

### Re: Distributions

So far on the mock test and other forums I haven't seen any probability questions. Also PMBOK and Rita does not provide any details on these areas. Experts please advice
coolpmp69
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Posts: 282
Joined: Mon Nov 17, 2014 8:55 pm

### Re: Distributions

Please disregard my previous post...posted it in the wrong thread. Sorry for the confusion
bs_pani
Super Member
Posts: 663
Joined: Mon Sep 22, 2014 3:36 pm

### Re: Distributions

Do we any thing called Logarithmic distribution.? For below question both A and B looks invalid example to me. But as per explanation ONLY A is invalid example.

Probability distributions are frequently used in Perform Quantitative Risk Analysis. Which of these is not a valid example of such a distribution?

A. Sigma distribution
B. Logarithmic distribution
C. Triangular distribution
D. Beta distribution

Explanation - The response 'Sigma distribution' is not a valid distribution. Continuous probability
distributions represent the uncertainty in values, such as durations of schedule activities and
costs of project components. Triangular, Beta, Logarithmic, Normal and Uniform
distributions are other examples of commonly used distributions. [PMBOK 5th edition, Page
337] [Project Risk Management]
signor_rk
Contributor
Posts: 182
Joined: Wed Jun 18, 2014 3:47 pm

### Re: Distributions

I think for PMP Exam , we no need to go very deep into the details of all forms of distributions. Here is a link to the Logarithmic distribution for quick reference:
http://mathworld.wolfram.com/Logarithmi ... ution.html
Regards ,

Ranjit
bs_pani
Super Member
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Joined: Mon Sep 22, 2014 3:36 pm

### Re: Distributions

PMBOK or Rita does not say any thing about it
shankars
Posts: 10
Joined: Wed Dec 03, 2014 7:07 am

### Re: Distributions

In PMBOK5 we have triangular and beta distributions(Pg-337) as part of Tools & Technique in Quantitative Risk Analysis.
IMO Beta distribution is more applicable.

Regards
Shankar
bs_pani
Super Member
Posts: 663
Joined: Mon Sep 22, 2014 3:36 pm

### Re: Distributions

Shankar,

its asking not a valid example. So certainly Beta Distribution is not a correct answer. Risk Analysis certainly does not use the Sigma Distribution neither does Logarithmic distribution.

Cheers,
Bhabani
shankars
Posts: 10
Joined: Wed Dec 03, 2014 7:07 am

### Re: Distributions

Agreed.

Regards
Shankar
coolpmp69
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Posts: 282
Joined: Mon Nov 17, 2014 8:55 pm

### Re: Distributions

Logarithmic distribution is log normal of the distribution
bs_pani
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Joined: Mon Sep 22, 2014 3:36 pm

### Re: Distributions

@coolpmp69,

Could you kindly provide an example
coolpmp69
Contributor
Posts: 282
Joined: Mon Nov 17, 2014 8:55 pm

### Re: Distributions

@ bs_pani

If you see skewedness of data especially in the right tail in the normal distribution then it is due to large number of positive outliers. In such case you would plot a log normal distribution of the same data so that you would get a closer to normal curve (of course Log normal distribution is not symmetrical like normal distribution ) as log value of any number/outlier is smaller their actual value.

Example: real estate properties value, oil prices, stock prices etc.
Hope this helps