Statistics 101: What are Combinations?
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- เผยแพร่เมื่อ 23 ก.ค. 2024
- Statistics 101: Combinations.
In this video, we discuss the basics of combinations as often learned in Finite Mathematics and Introductory Statistics. Several practical examples are provided along with how to calculate combinations by hand and using a TI-83+ calculator. Enjoy!
My playlist table of contents, Video Companion Guide PDF documents, and file downloads can be found on my website: www.bcfoltz.com
Your videos are literally saving my GPA! THANK YOU!
This video was frustrating because there's so many videos that don't show HOW they got the answer. Once I saw you not only go over the answer but show me how to punch it in my calculator I was so thrilled! Loved this video. Thank you so much!
Nothing constructive to add. Just wanted to say I love your videos. Thanks so much for doing them.
I love the way you make it simple to understand
The way you present the material is wonderful! Clear and concise. Well done! Thank you! :)
You are AMAZING!!!!! I'm feeling better with every video I watch! :) Thank you! You are a lifesaver!
I don't gamble and then shows how to gamble in a lottery! Classic. Hats off to you sir.
very clean and clear explanations!
Thank you for the encouragement! :)
So thankful for your videos!!!
these videos are very helpful. thank you very much. and i appreciate that bit at :50
The videos are awesome as it allows for great learning curve
I am a Computing and Engineering student/enthusiast and " This tutorial enabled me to reinforce my understanding of Permutations and Combinations as it all relates to Arrangements in Statistics. I can now practice questions successfully inclusive of more difficult theories and applications in Mathematics for Computing and beyond.
Thanking you for the Videos! "
Thanks Ryan! All the best, B.
Thank you Brandon....thanks a ton!!!
Thank you for these videos. They helped pass my MBA exam on Stats! They are informative and very easy to understand. One question, which calculator app do you use on your computer? And is it free or I have to purchase it?
thanks , this is amazing
Very clear and nice. Thanks.
Excellent!!
Finally I can go ahead n tell ppl ... i know what permutation and combination is ... hahaha !!!!!!!!
thank u !
Thanks a lot for the video, I want to learn more abut permutations and combination please give more about permutation. Monirul Hasan
Thank you!)
I just came across this video how would this apply to a Sudoku puzzle? The standard one specifically that has 9 numbers 1 through 9.
I love the scientific calculator!
Love you vids :D
Thank you.
Is there a solution set we have to follow by?
Thanks a lot, this is really helpful. (But you added an extra "million" when talking about the lottery probability - "twenty million (something) thousand fivehundred and twenty MILLION" making it seem a lot less likely to win (the lottery, of course, beeing basically a sure win :) ))
can we do the complex one please ? thank you
Thanks
Do you have a formula for combinations if there is repetition allowed??? What if someone wanted triple pepperoni on their pizza? or 2 pepperoni and 1 pepper?
Good! :-)
hi, thank you for this vid. can you solve for r in 7Cr=35 please?
R can be both 4 and 3. I am not sure you understand the concept after all these years but I hope you do well in your life.
Is there a formula to use ?
watch the entire video!
Good vid. On you last example your asssuming each lottery ticker is valued at $1 dollar. Aren't they worth more than that?
Where I live (and in many other places), each number combination you play costs $1. So a ticket with 10 number combinations would cost $10. But only the winning combination...wins, no matter how many combinations are on the ticket.
What if you had a specific combination in mind.
Is lottery cost for $1
isn't is 720. because. first you have 10 toppings to choose from , then it gets reduced to 9 and then to 8 so 10*9*8 is 720 and not 120. Can you explain please? My question here is why is it 10C3 rather than 10P3.
It's because you are forced to choose 3 toppings at a time. It's like how many ways you can pick three numbers from 1 to 10 for one time? The answer is only one. You can take any of the three numbers once at a time. Now, what are those three numbers is a different thing. First group can have 1,2,3 or 1,3,4 etc. In combinations you don't selectindividual items, it a group or set. So, you select 3 toppings out of 10, then what are the different combinations for that 3 toppings, hence 10c3. There no rule that you have to pick one topping first and then go to other, you pick a set of three toppings randomly.
How do you actually solve a combination problem? You show the answer and the problem but you don't necessarily show how you got your answer.
I believe that he assumes you are using a calculator. I know this is 7 months old but I hope this helps anyone else who sees it. Combinations equation: (n!)/[(n-r)!r!] Permutations equation: (n!)/[(n-r)!]
* n!= n x (n-1) x (n-2)... 3 x 2 x1
For example, 4!= 4 x 3 x 2 x 1 = 24
helped me man, thanks
helped me man, thanks
no prob
you have to watch the entire video!
Recreated the formula in Python.
import math
#####INPUT#####
n = input("Total group size: ")
r = input("Selected group: ")
######PARSING######
n = int(n);
r = int(r);
#####MATH######
group_factorial = math.factorial(r)
group_total_factorial = math.factorial(n)
parentheses = math.factorial(n - r)
x = group_total_factorial / (parentheses * group_factorial)
#####OUTPUT######
print("Total amount of combinations: ", int(x))
def count_combinations(n, r):
import itertools
return len(list(itertools.combinations(xrange(n),r)))
def count_permutations(n, r):
import math
return count_combinations(n, r) * math.factorial(r)
Too many examples without getting down to the math that shows us how you get the answers. You should start with a very simple example - - pose the question, show the results by using the math needed-- Immediately !, starting on video 1. For example P(4,2) vs C( 4,2) This shows the contrast and methods immediately. Your approach is too blah-de-blah. Get to it man, without all the hype related to definitions. SHOW THE MATH! , toss in the "how/why"and definitions during the examples, like horse racing, pizza toppings. So far - -yawn!
Examples are great but it would be better to use more visualisation
uh, you're not showing any solutions, just giving the answers