you make me want to burn my statistics book. I just spent 2.5 hours trying to understand a chapter and came out clueless, and then you made everything perfectly clear in 15 minutes (i paused a few times) YOU ARE AMAZING
The ASA Statement on p-Values: Context, Process, and Purpose www.tandfonline.com/doi/full/10.1080/00031305.2016.1154108 "Failing Grade: 89% of Introduction-to-Psychology Textbooks That Define or Explain Statistical Significance Do So Incorrectly" journals.sagepub.com/doi/10.1177/2515245919858072
I know Im asking randomly but does someone know a tool to get back into an Instagram account? I was dumb lost my password. I would appreciate any tips you can give me
Hi there, thank you Khan Academy this really helped me and its already 5 years since this was uploaded. I am so glad to be born into this generation of freedom of information online.
A clarification for anyone arriving directly at this video like me: the definition of the chi squared statistic for a sample is the sum of (x-E(x))^2/s^2, where s^2 is the variance of the data. When the variable is Poisson-distributed, like in this case, then you are in the particular case where s^2=E(x), as appears in the video
I have massive respect for your work, man! Thanks for making people throughout the world more educated, that´s one of the essential things this world needs. And it´s one of the essential things I need haha.
This material helped me out a lot! I know about khan academy since about 5 years ago and i just want to tell you guys to keep doing what you are doing, you probably account for more than 40% of my education
It's quite funny how every time you say "statistic" you have to slow down and make an effort to get it right. But seriously, I've watched most of your videos from the stats playlist and it's been a great deal of help. Thanks Sal!
Sal, another clear video. However, may be you could have talked a little bit as to why chi-sq is appropriate for this particular type of problem (or similar type) - how would a student know when to select the same distribution for a problem at hand.
@@TheMissionalNomad It's all good :) it happens to all of us. Sometimes I have ideas for new technology but then I check online and it already exists :P
The Chi-Square distribution is a sum of squares of standard normal variables Zi. What this test is doing is assuming that the squared errors between the observed and expected distributions are distributed ~ Chi-Square. Makes it a bit easier to understand the test when you understand the motivation behind using the Chi-Square distribution.
Thanks for the video, this just explains how to, but is there a video on why the difference between observed and expected follows Chi-squared test? And also does the expected distri (e.g. normal vs binomal vs possion) matter? what is the proof for that?
thank you so much :) question; do they always give you the percentage for the expected? because in all that i have done i had to either multiply the row total by the column total divided by the grand total or either dividing the total amount of scores by the amount of levels (the no. of days in this case) was i doing it wrong?
Hi ! In the chi square test, each random variable follows a normal distribution N(0,1). However, when you compute the sample chi square statistic, you add terms like ( (Oi - Ei) ** 2 ) / Ei. I don't understand how those terms can be seen as samples from N(0,1)
Thanks a lot for the explanation. What would happen if the random variables were not independent? Would it still follow Chi square distribution? How would it affect the degree of freedom?
Thanks for this video...I read the 1st couple of page in my Elementary Statistics book and was sooooooooo confused. You made this so clear! The only thing was your df (degrees of freedom)...I thought this was supposed to be number of columns minus one x number of rows minus one.
what is the explanation of when the number of sample goes up with same probability and pattern, the resulting hypothesis changes from accepting H0 to rejecting H0?
Hi! thanks for the amazing content. Just a little question on the assumed null hypothesis: don't we usually take the "NO news" kind of thing in null. I mean would it be more conventional if we state the null hypothesis to be: "Owner's distribution is incorrect"
Thats true, in his other video on "Chi square test for association (independence)", he mentions null hypothesis is "Negative". Seems like a contradiction. Did you find the answer?
The null hypothesis here should be that there is no statistical significance between the expected frequency and observed frequency (owner is right). As proven in the video, the null hypothesis is rejected. Hence, there IS a statistical significance between the expected frequency (provided by the owner) and the observed frequency. In conclusion, the owner is wrong.
@CogitoErgoCogitoSum this test is a non-parametric statistical test therefore you would use it when you cannot obtain the population parameters μ and σ
you make me want to burn my statistics book. I just spent 2.5 hours trying to understand a chapter and came out clueless, and then you made everything perfectly clear in 15 minutes (i paused a few times)
YOU ARE AMAZING
thank you so so so much for making this. you don't understand how much this helped me; my textbook could not have done a poorer job explaining it
most statistic books should be burned anyway
also statistic teachers
He is really amazing
The ASA Statement on p-Values: Context, Process, and Purpose
www.tandfonline.com/doi/full/10.1080/00031305.2016.1154108
"Failing Grade: 89% of Introduction-to-Psychology Textbooks That Define or Explain Statistical Significance Do So Incorrectly"
journals.sagepub.com/doi/10.1177/2515245919858072
I know Im asking randomly but does someone know a tool to get back into an Instagram account?
I was dumb lost my password. I would appreciate any tips you can give me
Hi there, thank you Khan Academy this really helped me and its already 5 years since this was uploaded. I am so glad to be born into this generation of freedom of information online.
It's 6 years since you made this comment.
Did you find ur role in this world?!
What do you do now?
But my dad didn't let me have access
literally the only video on youtube that gets right on the point! No bullshit intro, just right to point on what i need to know, Love it!
A clarification for anyone arriving directly at this video like me: the definition of the chi squared statistic for a sample is the sum of (x-E(x))^2/s^2, where s^2 is the variance of the data. When the variable is Poisson-distributed, like in this case, then you are in the particular case where s^2=E(x), as appears in the video
helpful, thank you!
I have massive respect for your work, man! Thanks for making people throughout the world more educated, that´s one of the essential things this world needs. And it´s one of the essential things I need haha.
This material helped me out a lot! I know about khan academy since about 5 years ago and i just want to tell you guys to keep doing what you are doing, you probably account for more than 40% of my education
you are the reason im getting a degree at harvard
Did u get that degree bro it's been 7 years can I get a update?
hes also the reason your degree is overpriced
I wonder if you had to also watch his videos to study for stat tests at Harvard ;)
@@bakhodiryakubov3981 I'm doing a Master in Physics at Oxford and I've found these videos more useful then my statistics lectures lol
@@randomman1000tweeny1 wow didnt expect that
it's relieving to read others in higher levels of school similarly benefiting from these vids. They're a lifesaver. Thanks Sal!
When the AP test is in 2 hours and you're finally trying to study 😬
Statistics is fucking impossible to study for. I've never taken such a dry class in my life
i study the time im taking the test
Why do you think it is boring? personally I quite enjoy it.
I’m actually cramming for a university exam in like 4hrs...
@@stoirmdraodih6810 same right now
Thank you so much! You just taught me how to calculate Chi-squared and my finals are tomorrow. :)
how was the exam? 4 years :D
How was the exam 8 years ago?
@@thewilmarvelfan 12 years?
Man, Sal, i thought i was done with khanacademy in grade 12 and here i am in my final semester of engineering :')
Thank you!! This example helped me a lot in understanding other purposes of Goodness-of-fit test. Really appreciate it!!
What a classic video!!!!.... Understood almost everything in 15 mins
so the p-value would be 0.043293 which is < 0.05 so reject the null hypothesis - same result as using critical values 11.07 < 11.44.
13 years ago , still holds its title for the best explanation ❤❤
This video was suggested by my bio professor & he was 101% right. This video makes it super easy :) thanks
1st year AP Stat teacher loves Khan videos... Thank you Sal :)
I have an exam tomorrow you saved me
Over 7 years and this is still very useful :)
12 years now
and its still helpful
graduate level student is learning from Khan videos... Awesome. thank you Khan academy.
It is very unfair to dislike this tutorial.
It's quite funny how every time you say "statistic" you have to slow down and make an effort to get it right. But seriously, I've watched most of your videos from the stats playlist and it's been a great deal of help. Thanks Sal!
Perhaps the best chi2 explanation that I have come across. Thanks
KhanAcademy + GPT 4 explanation is the BEST
Its Funny how I pay my professors/school thousands of dollars per semester and yet Khan always teaches me better for free.
Pay khan sir as well than if you feel like this
Sal, another clear video. However, may be you could have talked a little bit as to why chi-sq is appropriate for this particular type of problem (or similar type) - how would a student know when to select the same distribution for a problem at hand.
man this is a gem....
it amazing how well he writes with the mouse. It honestly amazes me.
Probably a digital pen
@@CrunchyDark 8 years ago I didn't know about this technology FFS looool
@@TheMissionalNomad It's all good :) it happens to all of us. Sometimes I have ideas for new technology but then I check online and it already exists :P
@@TheMissionalNomad surprised that you replied ! Do you get notifications of all your comments , I mean the ones which are like 3-4 yrs old ?
At last! Math & statistics feel approachable due to you. Thank you, Khan Academy!!!
Wow, that was a very nice example and intro to chi-square! Great job, Sir Khan!
This will go down as one of the most clutch explanations of all time
The Chi-Square distribution is a sum of squares of standard normal variables Zi. What this test is doing is assuming that the squared errors between the observed and expected distributions are distributed ~ Chi-Square. Makes it a bit easier to understand the test when you understand the motivation behind using the Chi-Square distribution.
Well explained,,,,thank you sir
Very explicit. Thank you.
Thank god for you khan academy.
Thank you very much.....excellent explanation
Thank you soooooooo much. You are the best teacher EVER!!!
great explanation!
Thank you got an exam in 2hrs
Thanks a bunch. It helped me with the homework.
This man is a storyteller.
Very nice, thank you for explaining this
Thanks for this test. Made it much clearer.
This was so helpful! Thank you Khan Academy and you guy who made this!
David Hager The guy who made the video is Khan, it's one guy that made evrything basically.
many thanks once again
Woah! I see and I understand! Thank you!
Fantastic video. I teach Stats & forgot how to do this. Great refresher
*subscribes as a thank you for cutting some of the unending stress I am exuding from my stats final in 5 hours* *nervous smile*
This cleared a few points up. Good video from Khan.
well explained and clear and easy to understand. thank you xx
thank you very much!
Wow you explained this so well, I actually got it! Thank you :)
hopefully the complete problem will be stated.. thank you
thank you soo much for uploading....amazing explanation...so much clarity
This is so beautifully done, many thanks.
I wish my high school trig teacher would just play your videos!
1:53 What is trying to be said with"a result more extreme than this". Is it a distribution that fits the Owners Distribution less ?
Thank you fam
THANK YOU
REALLY WELL EXPLAINED KHAN ACADEMY - WELL DONE
great teaching skills
Good luck students taking the AP statistics tmr! Pray for me guys
@neoaeonian
well, it is actually correct, because chi^2= Sum [ (Observed-Expected)^2 / Expected ] Note that the denominator is not squared.
Thanks for the video, this just explains how to, but is there a video on why the difference between observed and expected follows Chi-squared test? And also does the expected distri (e.g. normal vs binomal vs possion) matter? what is the proof for that?
i dont have enough words to thank
it's funny how you always repeat yourself but that makes your video's so easy to understand! thanks for your help!
Thank youuuu it really helped 👍🏻💙
Saved. My. Life.
AP STATS exam today, thanks alot!
really great, thanks
Well explained, thank you!
superb video
Great explanation and sample. Just what I was looking for. Thanks.
Thankyou very much for this, the explanation is so clear and so good.
Amazing Help, 5/5.
I feel this initial presumption is wrong. Null Hypotheses should always start with "negative".
Awesome explanation
thank you so much :)
question; do they always give you the percentage for the expected? because in all that i have done i had to either multiply the row total by the column total divided by the grand total or either dividing the total amount of scores by the amount of levels (the no. of days in this case) was i doing it wrong?
awesome! Thanks so much!
Hi ! In the chi square test, each random variable follows a normal distribution N(0,1). However, when you compute the sample chi square statistic, you add terms like ( (Oi - Ei) ** 2 ) / Ei. I don't understand how those terms can be seen as samples from N(0,1)
Did you finally understand them?
THANK YOU :* video is comprehensible :)
Thank you - this was so helpful!
Thank you for that Sir.
Thank you. Thank you. Thank you!
Turns out I actually do get Chi-Square Test after watching this.
Thank YOU so much!
haha and 8 years later after you wrote this, another soul somewhere was saved too. haha
Thanks a lot for the explanation. What would happen if the random variables were not independent? Would it still follow Chi square distribution? How would it affect the degree of freedom?
i suppose usually for simplicity sake we always assume random variables are independent
thank you so much
Thanks for this video...I read the 1st couple of page in my Elementary Statistics book and was sooooooooo confused. You made this so clear! The only thing was your df (degrees of freedom)...I thought this was supposed to be number of columns minus one x number of rows minus one.
AP Stat Test Tomorrow, life-saver!
Hey can you do some videos on error propagation to go with your statistics videos?
thanks
ik its been a decade but thank you so much, hypothesis tests in general confuse me a lot
thank you
what is the explanation of when the number of sample goes up with same probability and pattern, the resulting hypothesis changes from accepting H0 to rejecting H0?
Hi! thanks for the amazing content. Just a little question on the assumed null hypothesis: don't we usually take the "NO news" kind of thing in null. I mean would it be more conventional if we state the null hypothesis to be: "Owner's distribution is incorrect"
Thats true, in his other video on "Chi square test for association (independence)", he mentions null hypothesis is "Negative". Seems like a contradiction. Did you find the answer?
@@2828jordan I have the same question here. Anyone find anything?
The null hypothesis here should be that there is no statistical significance between the expected frequency and observed frequency (owner is right). As proven in the video, the null hypothesis is rejected. Hence, there IS a statistical significance between the expected frequency (provided by the owner) and the observed frequency. In conclusion, the owner is wrong.
Thank U!!
thanks for the good video :)
thanks man...
is there another video like this where it shows the formulas for each step? thanks
@CogitoErgoCogitoSum this test is a non-parametric statistical test therefore you would use it when you cannot obtain the population parameters μ and σ
So you would use this Chi Square goodness of fit test to determine whether a set of data came from a particular distribution?