Range, variance and standard deviation as measures of dispersion | Khan Academy

[@zinaalabdaly6848]

And here i am, 10 years after this was posted, learning more here in 12 min than my course in an hour Thank u from the heart of mine, khan academy !

[@vincentdrew2194]

I played this at 2x speed to learn it in 6 min

[@owenpatenaude1072]

Same lo

[@I_unar]

@@vincentdrew2194 That’s not smart, you might not understand everything because your brain can’t catch up. Don’t try to get everything done as quick as possible, sometimes it causes mistakes

[@rapemap]

reviewing simple explanation after hours of complicated lesson often give you a new understanding and you feel enlightenment.

[@sachimoo]

I am taking a Statistics class online and YOU are by far the BEST thing I've come across! Your explanations are clear and thorough. You cut through all the STATISTIC jargon and allow the student to conceptualize the theory of basic statistical analyses & problems. You are truly Gifted!Thank you for sharing your knowledge and Passion.

[@coyomedia1310]

right! thats facts! my statistics professor talks so confusing and quickly! I had no choice but to find other videos to study for our weekly concepts! I couldnt go out like that!

[@harijsijabs2420]

This made so much more sense than my university professor. Thanks a lot!

[@edthoreum7625]

great work but #are so small and the board is so dark?

[@Anonymous-ko5ug]

Harijs Ijabs why are you learning this in university? I'm learning this in the 6th grade

[@FloydFilmz]

bcuz we all have specific concepts we are learning in college such as criminal justice or law or engineering. But there are a few courses that you have to repeat that u've already learned in middle and highschool. Thats why kid.

[@azimtwice]

+FloydFilmz why'd we pay thousands to repeat what we've already learned?

[@oliviaso9726]

@@azimtwice idk

[@krossthug]

i cried cos this helped me so much

[@Zmunk19]

did it sound something like trololollololololoololollololol

[@videogamejo]

***** Right? Isn't Khan amazing? Khan Academy makes me realize that math isn't so bad when explained properly. So many teachers and books explains things in a cryptic manner. Khan explains this stuff in layman's terms and it just clicks.

[@madrid7790]

Did you pee yourself too?

[@ammaraa3287]

Same!!! In class I was like what is this even and here I understood it 😂🌸🌸

[@memoo2133]

JJ not math, its statistics.

[@murators4732]

Please never delete your videos. I am also 10 years after posting learning this stuff and you are the only one who explained it the way i could understand and use it. Youe helped, help and will help millions of people. Thank you

[@fabbabs]

I have studied these concepts in at least three different classes and never understood them as well as I do now. Thank you.

[@Supremepie]

Khan academy... helped my 14 year old self, and still helping me at 24 years old, God bless you.

[@0nly1w0rld]

This guy has done so much on Khan Academy, he should be nominated for the Nobel Prize in Education. If there isn't such a category, they should create one

[@StopwatchRobert]

You know Mr. Khan, you and you alone are the reason this program works so well. What you teach is no different than a university professor, but the way you teach it squeezes more information into a 12 minute video than I'll get in a 50 minute lecture, and I understand it much better. I think I speak for everyone when I say I wish you were my teacher, you'd be absolutely perfect at it.

[@kk8490]

Oh my god yes. Not all superheroes wear capes

[@lkerzgrl24]

Plot twist: he was wearing a cape

[@whitewalker608]

@@lkerzgrl24 Plot twist. OP is talking about Iron Man.

[@kavyasoni139]

​@@whitewalker608plot twist he is talking about Superman 😂

[@Clurf]

Plot twist. The entire plot has become twisted.

[@BrianKouhi]

Amazing teaching skills, i've struggled to understand this in university for the past 2 months, with my prof being of little use. first time watching this 10min video and i completely understand it now! Thank you!

[@122willman]

just goes to show these universities are so overrated. they don't teach anymore. About to graduate myself and it is so funny what university teaching has become.

[@jeremyrodriguez4989]

Currently a history major with a minor in political science. Took statistics in high school and again in college but this just made so much sense. To anyone reading the comments, watch frequency tables first and then start looking at this video. It takes15 minutes for both but you'll appreciate so much math quickly.

[@HannanAli]

If only you guys could see how the teacher teaches this subject at my university...You'd hate this subject i guarantee. She straight up reads solutions from the guide book without explaining whats happening or why we are doing anything.... Thank You So Much Khan Academy!!!

[@Lani2722]

Everyone is talking about their professors in university and how they're useless like 7-2 years ago I'm here in 2020 trying to figure this out in high school because I hate remote learning.

[@Lillith9008]

that sounds very difficult dear, i can't even imagine having to do high school right now. i'm sorry you have to go through that

[@gracemostek1976]

same

[@janaaa9309]

me too

[@ikyouknoweknow]

@@Lillith9008 thank u for being compassionate

[@coolshante7093]

There am I scrolling down and liking every comment coz I can relate to them

[@dotted_stains2792]

Seeing how you have 142 likes....... I wonder

[@saulmatakarawa9236]

Very well explained. However, I find another explanation stating that the denominator in variance calculation should be n-1, which in this case should be 4 (5-1=4). Please clarify. Thanks

[@manveersingh7842]

+Saul Matakarawa I believe n-1 is to calculate the sample variance. Not 100% sure, but from what I remember.

[@Alex-zc9ty]

somebody else explained please

[@aoa0687]

vortex.ihrc.fiu.edu/MET4570/members/Lectures/Lect05/m10divideby_nminus1.pdf Check page 2

[@pppkaew4297]

Sample Variance’s denominator is n-1. Population variance’s is n

[@vijayanandvadhyar7224]

@@pppkaew4297 thanks

[@nelsoncastillo7888]

Your method of teaching is comprehensible, thanks

[@Notabot2000]

Learned more with this video than the first 3 weeks of college with my useless professor

[@ZoZo-sk7mq]

Hold on you r learning this in Uni then why am i learning this year 9 or 9th grade AUstralia IS messed up

[@herat3158]

College? We're learning this in grade 9 though

[@ZoZo-sk7mq]

@@herat3158 thats what i said but in australia we call college uni

[@lily-er5xt]

I’m learning this in 7th

[@gacharaeztrid7620]

@@lily-er5xt yeah, same.

[@coreyw2124]

You're so clear and cut through the jargon so well that it's actually making me mad. I spent so much time in college trying to understand this stuff and if I would have just watched these videos instead I can't even think about the amount of time and effort I would have saved. Great stuff

[@minhazulislam4682]

hopefully you found that useful... it was the most easiest explanation I got on the internet..My university life started a few months back (online semester ft. Corona) and I am taking a Stat course right now. My teachers explanation was really vague, it's like he(my teacher) is trying to hide something from me. but this actually cleared everything up. Thanks Salman. One day, I will be great teacher like you inshaallah.

[@Mahmoud-ys1kt]

Simply , Its Great . Thank you

[@fangtzukang6163]

The most helpful explanation about standard deviation I've ever watched. Thank you so much, Sal!!!! You're the best math teacher in the universe.

[@user-zr4od4qg7s]

I been sick for the past week and my friends told me about this because they are learning at school so I got worried since they said there's a test tomorrow but this helped a lot THANK YOU now I'm ready

[@HAMID___]

Thank you u explained it so seamlessly 😭👏🏽. U save me from failing a test

[@ntbarnes656]

such a great breakdown!! thank you!! you explained every step so that I understand what I am using to get each answer.

[@coronnation8854]

You have been helping me pass university classes for the last decade. You're a very important person in the world.

[@mariellesiapno2494]

Thank you so much for this!!!! ♥️ You’re a blessing! ♥️🙌🏼

[@IIXIXOXIXII]

You spoke at a great pace and very clearly. This video was very helpful. I would like to know what the answer to evilshenanegans' question is though.. and william's question on negative numbers and range...

[@yrebrac]

Khan, you legend. Needed a quick primer on this topic. You are the man.

[@sabrinadiego3586]

You did a great job. I followed the lecture and I could not understand. I saw your video only once and I realize that it is very easy. I think because you explain very well. thank you very much.

[@wiifreak911]

This is the "Population Standard Deviation" For the "Sample Standard Deviation" we replace n with (n-1) to ensure that all desirable properties of an estimator are retained.

[@gracefredericks2126]

This is so helpful!! THANK YOU. You actually repeat what you're doing to help to get it in our brains and for me, it works! I didn't have to keep scrolling back. (And it also helps that you don't have a ridiculously boring monotone voice like a lot of the people who make these maths videos do)

[@aishaabaniel6827]

Tanx God i found the best teacher here even you tube.nung nag aral ako walan akong naintindihan.thank you so much Sir for your help.God bless u Sir

[@jekamiahruiz6500]

This is cool. You have helped me a lot. Thanks to you 😊 I've also watched your videos on several topics in physics. Galing nyo po!

[@MichealOliver-y5q]

Fantastic explanation I've always found range, variance, and standard deviation frustrating. This video really breaks down these concepts in a way that's easy to grasp. Please share more such videos. For anyone else struggling, this video is a game-changer. Plus, I've also been using free textbooks from SolutionInn to better understand these concepts, and they've been a huge help alongside this video. Pairing it with resources like SolutionInn, Chegg, or Course Hero offers extra practice and explanations that solidify your understanding. Thanks for making this topic less daunting!

[@bryanjy7923]

From algebra to calculus, to history, and also to statistics?! WoW! so amazed. Is Sal Khan the one that discuss in most these videos? Is he a genius? Or other way around.

[@hubdarali8633]

I have learned this topic different videos lecture but your lecture is conceptualize and clear my all confusion...thanks❤❤

[@saravaliyeva2591]

Thank you so much for your video and explanations .I started Statistics classes recently and i also learn more from here than from my professor .It helps really thanks a lot again

[@Abhishektheunofficial]

Thank you so much. This is so helpful. I highly appreciate the time and energy taken to prepare this to make this available for free.

[@krishna_kk007]

I calculated -20 squared and it was -400. I am not saying you're wrong I just doubt that equation. But other than that you're an amazing teacher. Keep up the excellent work Khan!

[@sameedsherazi]

I don't know why but I am in love this guy's voice. And yeah the lectures being the first.

[@renatarech2429]

Oh wow!! I don't normally comment of KZbin videos, but you just took something that I found so confusing and complex and broke down until it was simple! Thank you ever so much

[@timenotime]

this is SUCH a good video. i am doing a course in stats for uni and struggling so much because it's been years since i did maths (never been good at it) and i'm so happy i found this video because it's cleared up so much of what was confusing me about this whole SD vs. variance business

[@silentlessons4221]

Khan academy at it again with an awesome explanation and breakdown of statistics. Thanks very much.

[@fancydeer]

Seriously saving me in my college class. I didn't understand any of this, it's amazing what a difference a GOOD teacher makes.

[@pietatk]

I don't have enough words to thank you! You helped so many people, including me. Truly, thanks so much :)

[@danamclemore3805]

You rock - as usual. You are sooo amazing.how many people have you helped ??? You will never know

[@marysadek9683]

This is amazing! I thought I hated stat until I watched the video. It turns out I have a bad teacher lol . The teacher who made this video made it simple and conveyed the meaning in a great way! Thank you:)

[@moizkhalid2714]

Any time you feel struck in mathematics, you tune into Khan Academy where Sir Sal explaining the concept so easily.Another day is saved,thanks to Khan Academy.

[@djchillsbx1]

yes indeed this explians it a bit better than all the other class material. Thanks!

[@trombonetribute6433]

It's summer I'm 13 and I'm learning it's my best summer yet I understood standard deviation from my math book I just didn't see that variation was standard deviation without it being square rooted it's so easy

[@eduugr]

Thank you. You are really good explaining !!

[@muhammedrajab2301]

Awesome video and great explanation. But one quick correction, 9:48 Distance can't be negative or zero.

[@ExploreLearnEnglishWithGeorge]

a video explaining sample variance and population variance would be helpful.. (my synapses are shutting down)

[@williammagdales2330]

Dude, now im ready for my periodical test, tommorrow !! I really appreciate you pal !!!

[@saadhashmi511]

Found this vedio in my 3rd year of med school and was saved in Biostatistics. Alhamdulillah

[@88spaces]

Your explanation is very clear and simple to understand. Thank you.

[@waterfairy2011]

First time in my life I understand what is variance. Thank you so much!!!

[@sindizwane7482]

I love your explanation really but I am bit confused with SD (standard deviation) but I will go back toy book and listen to this again. Thanks 🙏🏿

[@kevinrandalrulach]

I know these stuff 100%, but I need to understand these stuff with 300% confidence. Thanks for the upload.

[@bsayah]

Oh my god, this never made so much sense before...thank you so much!

[@denzilseukanundun540]

I need this channel for Data Science! Thank you Khan Academy!

[@ppl_call_me_tima]

Thanks a lot! Really simple and useful comparitive explanation!

[@bcasarez]

The video is correct because he dealing with a population data set (also evident by the use of the sigma symbol). He explains this @ 4:45 - 5:09. You only use (n-1) when you are dealing with a sample data set (where you use "s" and not sigma).

[@PlanYourLift]

This is great and I was nodding my head, smiling, understanding everything up to where you did the standard deviation. When you did the square root thing, how did you find out it's 10√2 and not just type into your calculator √200 = 14.14 ? Do you not actually work out the square root? The variance for the second population was 2 and the standard deviation also 2, why don't you square root 2 (√2=1.41) for the S.D? Thanks

[@arsnova03]

The reason why he did that is because 200 is equal to 100*2 and by propierties of exponentiation, √(100*2)=√100√2=10√2. √2 is a number like any other number, it's not necessary to "work it out". Sometimes we like to do it that way because it gives us a more of a feel for where the numbers are on the number line. I don't know where √650 is on the number line, but 25.5 is pretty clear. It might be easier to see where 14.14 is on the number line than 10√2, but 10√2 looks prettier to me. It's just a matter of personal preference.

[@PlanYourLift]

i see. its cool you see some numbers are prettier than others, you must somewhat have a passion for math.

[@arsnova03]

It's a very useful tool, but I don't like it very much. I study it because I'm an engineering student. I hope you are enjoying your education, it's a great privilege!

[@hugojj101]

Ha, watched Khan academy vids when I was 10 and here I am 6 years later using them to help me with my as levels

[@nikkishivoy9921]

The video helped me a lot in understanding Standard Deviation.

[@tasbeehdeyaa]

Thank you so much. This.. This is exactly what I needed. It made me realize I'm not slow nor stupid it just depends on who the teacher is.

[@hoomanazizi8969]

I studied finance in uni and our master could not explain it as simple as this in a whole semester. thanks

[@samizaki7165]

The perfect way to understand the variance and the standard deviation ... Thanks KHAN Academy

[@watchlearn3943]

Well explained. Now I was able to relate all these things. Thank you very much.

[@samanthapikus3178]

For the square root of 200 I get 14.142... How am I understanding this wrong... Great video. You are a really good explainer.

[@Yud_Trinitarian]

1. explain how you determine if a graph has high or low variability 2. Explain how you determine if a graph has high or low statistical bias. 3. Explain the difference between stratified random sampling and cluster sampling.

[@techvishnuyt]

13 years later, yup learning from here more than my professors

[@A11Omar]

very useful. I'm taking QUAN201 and I wish I had you as my instructor 'cause mine really sucks

[@ayeshafaiz3582]

Thanks Allah that khan academy axist on youtube..so much helpful.such a great explanation..

[@ioannismarkoulakis4978]

I normally just like the video but, this one deserves a comment. Good job, great explanation!

[@ahmedamr8496]

Transcribed image text: If you have the following measures for two samples: Sample 1: mean = 15, variance = 7 Sample 2: mean = 7, variance = 15 Which sample has a larger range? ??? can anyone tell me the answer please

[@Naked_Snake]

Haven't really used Khan Academy before, but I used this for Economics and makes perfect sense. Thank You.

[@Czathero]

OMG! I love you! I finally understand this now! So happy!

[@kishwarbhuiyan743]

This video has helped me a lot to understand standard deviation and variance.Thanks a lot Khan Academy.

[@Naturenest7-v6k]

Thank you so much, 🙏 your channel is the best, this makes so much sense than my Uni professor!

[@raquelporras5895]

Is it just me or does he sound like old Ted Mosby? Great video btw, I've been watching them before class and they are super helpful!

[@ahmde]

Great explanation, very intuitive.

[@regineyu34]

Your videos really help me get through my statistics class, thank you 💕

[@josecuervo1646]

I need Sal to take my SAT for me.

[@brokenballer89]

OMG this clip..... how can you explain these things in such a easy way. Thank you!!!

[@Germel16]

Your awesome I completely understand everything. I been having a hard time in this class but I think I understand it a little more now thankx

[@qobiljonxayrullayev3635]

thank you very much lesson was reallay enjoying you understanded the this in 12 minutes that i did not understand 2 hours

[@clarencekeller7684]

omg wow thank you so much. Made it look so simple while my study book made it the equivalent of common core math!

[@ninagetmoney9321]

thank GOD for you!! I was stressing in class. you just made it super simple for me!

[@dawoodali4605]

Thank you soo much man!!!! Came in clutch!

[@StayMotivatedWithKrantiGaurav]

The sample standard deviation of the dataset 2, a, 12, 18, and 30 is 10.8 (correct upto one decimal place), where a is an unknown quantity. Then, the value of the sample variance of the new dataset that is obtained by adding 5 to each number of the given dataset is __________.

[@XinhLe]

Thanks so much (from Southern hemisphere)!

[@marj736]

Khan, you are a life saver!

[@hariiiprasath]

Here I am, trying to actually understand these concepts 8 years after school, and this 12 min video made me feel like my schooling had failed me.

[@gurpreetbhalla]

your videos are too good and i think u are doing a great job

[@kajendrarana1847]

thank you for your clear explanation.

[@Neutrino22]

Your every videos on mathematics is awesome. I have learned so many things. Love youuu

[@Equistta]

Thanks for showing me on screen what those terms mean. When i was reading it in my statistics book, i got lost on variance, and standard deviation. Now i understand how to calculate it... but i still don't get whats the point of doing all that in the first place?