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Graphical Models of Probability
Bayesian Networks, Decision Networks, and Probabilistic Relational Models
Hello everyone, I'm taking the math exam to reenter the college… 
24th-May-2005 11:32 am
Hello everyone,

I'm taking the math exam to reenter the college world, as my ACT scores no longer hold any value, since they're 11 years old. I'm reading a refresher math text, but I've come across something that for the life of me, I cannot recall ever doing and cannot grasp. I'm a very logical person, so if someone can explain "Permutations" to me in a way that is utilitarian and not just a jumble of formulas, please help. Also, Pascal's triangle is baffling, and as it applies to this as well ...
24th-May-2005 06:36 pm (UTC)
hahahaha I've actually already looked at that, and it doesn't help me at all.

24th-May-2005 06:43 pm (UTC)
ok - say we have a bag filled with 4 types of blocks and we want to take 2 blocks out of the bag at a time. How many different sets of two blocks could we possibly get? That is a permutation question.

You might look here http://mathcentral.uregina.ca/RR/database/RR.09.95/nom1.html

for more help
24th-May-2005 06:52 pm (UTC)
EEek... Okay, so I actually get the whole how many variations of CAT can you get. Thats not what I have problems grasping. Its the formulas that I don't understand; the fusing of Pascal's triangle perplexes me as well.
24th-May-2005 06:59 pm (UTC)
the example of standing in line from the second link is probably more useful in this situation - are you familliar with factorial notation?
4!= 1*2*3*4 - you simply take the all the numbers between 1 and whatever number and multiply them - so n! = n*(n-1)*(n-2)*(n-3)...(n-(n-1)) - does that help?
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