ck12.org normal distribution problems: z-score | Probability and Statistics | Khan Academy

Courses on Khan Academy are always 100% free. Start practicing-and saving your progress-now: www.khanacademy.org/math/stat...
Z-score practice
Practice this lesson yourself on KhanAcademy.org right now:
www.khanacademy.org/math/prob...
Watch the next lesson: www.khanacademy.org/math/prob...
Missed the previous lesson?
www.khanacademy.org/math/prob...
Probability and statistics on Khan Academy: We dare you to go through a day in which you never consider or use probability. Did you check the weather forecast? Busted! Did you decide to go through the drive through lane vs walk in? Busted again! We are constantly creating hypotheses, making predictions, testing, and analyzing. Our lives are full of probabilities! Statistics is related to probability because much of the data we use when determining probable outcomes comes from our understanding of statistics. In these tutorials, we will cover a range of topics, some which include: independent events, dependent probability, combinatorics, hypothesis testing, descriptive statistics, random variables, probability distributions, regression, and inferential statistics. So buckle up and hop on for a wild ride. We bet you're going to be challenged AND love it!
About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content.
For free. For everyone. Forever. #YouCanLearnAnything
Subscribe to KhanAcademy’s Probability and Statistics channel:
/ @khanacademyprobabilit...
Subscribe to KhanAcademy: kzbin.info_...

[@berry.x9388]

"how many standart deviatons away from the mean" this simple explanation was all i needed. my "proffessor" who has "worked on biostatistics for 30 years" tried to explain this to us for 25 mins and when she couldnt she accused us of not knowing any math. thank you for the video, khan academy

[@Chloe-gh6mg]

True. I just come here after my STAT online lecture(my prof is well-known for the bad teaching skill🤦🏻‍♀️

[@berrie7098]

literally here taking biostatistics as my first stats class ever an couldn't agree more!! that one sentence was sooo needed to put it all together !!!

[@maykaa4000]

lmao yea just blame it on the teacher

[@danal8246]

@@maykaa4000 Ur watching the same video bozo

[@layth.rokage4943]

thats hilarious🤣 @@danal8246

[@bethmacdonald176]

I cried while watching this video because it FINALLY made sense. I've been trying to figure this out since the beginning of the semester and you made it so clear. Thank you. Thank you. Thank you.

[@imamulmalikchowdhury7659]

You learn this in university ?

[@schanemassey3861]

Yes! This is taught most lower level math university classes :) I'm guessing you learned this in 2nd grade huh? #aren'tyouaGeninus

[@traviswilson36]

You must have not learned grammar though

[@nitamac1312]

lmfao why are you flaming him soooo hard?!?

[@sophikolomineishvili7109]

@@schanemassey3861 yes it is taught at Universities, even at grad level. However, depends on your major, I personally study this in my research and analysis class, I don't think I ll ever use it in real life :)

[@ayannabrown7303]

I know you get a lot of comments thanking you, but I don't think you understand how much I genuinely appreciate you!! I've been watching your videos since my freshman year in college and you've helped me tremendously. Thank you. God bless your heart.

[@shayanahmad1451]

I learned more from your videos than from my entire time in colllege

[@sumit121285]

me too....

[@fnmav]

3:50 "Let's do a couple more, let's do all of em" Love the attitude ! :D

[@rachelchu5363]

I cried. Imagine if i learnt statistics from you, i would get my statistics 100% mark. Thanks for contribution. A great teacher is the most notable role.

[@TriniSecularHumanist]

I cannot begin to thank you for simplifying what I have been doing in class for the past month! Thank you for explaining what z-squared means!!! We were taught how to calculate but not what it means. I just experienced multiple epiphanies. Thank you so much for sharing your knowledge online for free! The world is a better place for it!

[@praptiadhikari9054]

your videos are so much fun and appreciated by everyone classroom lectures make us yawn all we wanna say is thank you Khan

[@sofiapraderio7441]

I watched countless videos about this and this one was the one that truly made me understand this perfectly. thank you SO much!!!

[@scottparsons7825]

Once again you have taken a concept that was presented in a confusing manner in my book and made it ridiculously simple! Thanks!

[@nubianmaat3322]

Who ever you are teaching this concept, I hope the gods smile on you lol! Why is it that no one could explain this the way you did!? Thank you so much for having the ability to teach as if you're teaching a child! You are so awesom!

[@pawality5725]

This is the best example I found yet. I am still struggling with with STATS and this has open my eyes up a little more. Thanks a lot

[@sampleaccount789]

This is my first video and I have fall in love with Khan Academy. Dude you are super awesome. Keep going.

[@TheMunkzilla1]

Thank you. This finally makes sense. Textbooks over complicate things and when taking statistics courses online with no actual classtime this is a lifesaver!

[@Anam7145]

Mr. Khan always explains my one hour lecture classes in less than 15 minutes. Awesome.

[@MiguelBandito1988]

Thanks Professor.. You made this so simple.

[@WhatIsThatBlueStuff]

I went from stressing out to acing stats thanks to this guy

[@barbaradonohue4822]

Ten years. It’s been ten years. Still remember? Lol. I’m just learning 😢 7:47

[@dirpydinonuggetswithketchu135]

Even after 13 years it’s still helpful because my professor is so quite I can’t hear half the things he says 😂

[@greymollusk]

Khan is the stuff of legends! All Hail Khan!

[@gorgjesss]

pretty helpful, this stuff is going to be on my final exam. It is pretty new to me, but I have been getting it with the help of drawing the bell curve and the z-score formulas. so thank you for all your simple explanations and help!

[@Momofwaterchild]

My statistics professor knows his stuff but cannot teach in a clear and simple method, which these videos do. So, thank you very much, you have helped tremendously!

[@Sheena000]

Bless you sir. Final exam is tomorrow and I have to learn the last unit rn.

[@loriluo8359]

thank you so much, you are the best math teacher I have ever met! 🙏❤️

[@Richard24Blair]

I'm attempting (and until recently, failing) to take Statistics right now, and you are a god to me thanks to these videos.

[@CiscoBerrones]

Finally it makes sense!!! Thank you for this video!

[@gabyaguilar3552]

I'm pretty sure that I'll get an A in my math test tomorrow. Thank you so much!!

[@haleywang8941]

why can' t college be khan academy

[@benjaminroscoe3690]

it kind of is now... this aged really well

[@haleywang8941]

@@benjaminroscoe3690 LMAO I forgot that I had written this

[@celiaalcantara4651]

I believed I WOULD NEVER understand this formula to calculate z scores and I just GOT IT! I BOW TO YOU SIR!!

[@QuillWorks]

0:22 My ears: “A mean of 81” My head: “A mu of 81”

[@charlescapehart3556]

Thank you!!! I swear they made this so difficult for no reason!!!!!

[@danielaalmendaro8470]

Thanks for the help my final is tomorrow and I’ve been studying this whole week since it has to be accumulative🙄

[@michikosmith3262]

Every stats prof needs to just make this video part of their lecture

[@kellytones9104]

Thank you soo much, perfect

[@Th30bserver]

Thank you so much. This saved me from wasting my no-homework pass on a easy concept.

[@Alison7292]

OH MY GOODNESS. Thank you

[@brampyvich]

Great Video, Thanks Khan...

[@juan57547]

Man your handwriting is nice

[@Bapewatch01]

thank you !! wen u describe each step properly i understand wat ur saying, u r cool :D

[@chittiprolurammohan2415]

That is Khan! Great Bro! u unclose my doubts in Z score definition= no of Sd away of mean!

[@toramali]

You are a blessing on earth

[@71318elmo71318]

Thankyou, exam tomorrow, big help!

[@teachersimprint]

Thank you. Clarification!

[@angelicamontanez8372]

Here is to this still being absolutely amazing

[@majormuss]

can't thank you enough.. keep it up!!

[@AhJodie]

Sal, you are so brilliant!!!!!

[@MsPerva]

You are the best 🌹🌹🌹

[@macbisda6303]

Thank you very much!

[@jeromepringle4949]

Great video!

[@shades45501]

thank god i needed this

[@Lizdepina]

I think I'm in love with you....You are a statistics GOD! Thank you!!!!!!!

[@franklincarpenter5431]

Thank you!

[@nikhiljoyappa687]

Excellently explained 👏

[@murridithvines]

Thank you!!!

[@genresanfuego4314]

He is a better teacher than my math teacher😑

[@andrewl1024]

WOW! Mind blown.

[@KCTOOREAL]

God bless khan academy🙌🏾

[@paulceltics]

thanks man this saved me

[@jababyxd]

Big help!!! thank you :-)

[@joannemamo8177]

Amazing thanks

[@ZachGRocketBossZach]

Kahn, you're great; I just wish your videos were louder.

[@noobkosh]

another saviour video

[@Iamatheist1234]

hes' a science and math god.

[@sunshinegamas331]

Thank you very very much i am smart in math i am bullied because of this thanks because i find this thank you very much😭😭

[@lolscience1979]

All the ninth graders in Honors Algebra 2 will thank you this night before the quiz!

[@stevegrca]

wow. thanks a lot

[@myenmoni]

You are awesome!

[@pblack68]

Love your handwriting

[@eainpower5670]

good explanation

[@Johnny.bar99]

why am I paying for university, I'll just subscribe to this guy and put it on my resume

[@kare917]

Thank you ❤

[@Fsp01]

Life saver.

[@onyxora]

If a z-score is a measure of how many standard deviations from the mean, does it matter if your results are "normal" (bell curve) or can they be skewed right or left and still use the z-score to identify if data is more unusual based upon distance from the mean?

[@The4416deb]

Thank you

[@Vleertouwer]

Good for you.

[@shazaduh]

love it.

[@cottonjun01]

Thank u so much 💓 😭

[@JustHuman8]

wish i found this before my final exams :(

[@MizzC625]

Yaaassss!! *lightbulb*

[@Polo-715]

I think I learn better through videos not gonna lie

[@shetsangtenzin]

5 minutes is all it took for me to understand the concept watching this video and my class professor took 3 class session on z score and yet failed

[@stevenconner3417]

Let's use a z-score in statistics for Optometry so that all C interfaces private and public for example time clocks when someone is 50 years old they don't have to use the readers to do the same job

[@lizzchoate]

Please help me figure this out....I need your amazing teaching skills!!! On a standard measure of hearing ability, the mean is 300 and the standard deviation is 20. Give the Z scores for persons who score (a) 340 (b) 310 (c) 260 Give the raw scores for persons whose Z scores on this test are (d) 2.4 (e) 1.5 (f) 0 (g)-45

[@pratapkumarmishra8297]

a) 2 b) 0.5 C) -2 Use formula: (X-u)/c=z U= mean and c=standard deviation. In first three cases x is in options and z is to be calculated. Reverse in next three cases

[@fadwa2413]

i love you man

[@kyrahdames8215]

what is the formula before solving random numbers in

[@raymersonjaymesduad720]

It all makes sense now The pieces are falling into place

[@justme-iv5yq]

Now you’re talking my language

[@Hendrixtv44]

Sir I would like to ask a question. I see the answer for c gave us a decimal. Does it mean in Z-score Normalization we can't round up the decimals? Please I am new and which to know more. thank you.

[@JakeLo1991]

ALL YOU NEED IS DESIRE.

[@INSANExSAMURAI]

How do you know when its negative or positive, cause on A you did -16 but on B you did positive 2 so how do I know if its positive or negative?

[@hoduonghai7936]

My FAVOURITE channel from now on, unsubcribed every other channels, thank you x 99

[@Zaloomination]

This is great, my class's powerpoint presentation made NO sense. Why can't they explain it in clear terms like Khan?

[@oiiirich]

I hate statistics but Sal makes it cool. :)

[@VanessaLopez-xo4yo]

Found this video very helpful as it will be on my CPCE exam for graduation! I’m just a little confused regarding the answer (A). Is it because it’s closer to the mean? Sorry I know it’s a very silly question and yes the video was helpful I just don’t understand why (A) is the answer ! 🥺 please help 🙏🏼

[@praptiadhikari9054]

why do/how can exam grades follow normal distribution?

[@paulhetherington3854]

6.3? 6+-3 = 9:3 = 12:6 - calculus rules: Laarjist till lilist

[@IgorAherne]

In HD ;)

[@beartribe4938]

What if standard deviation is not given

[@chariots8x230]

What I don’t understand is how you mapped these z-scores on the bell curve. How can I calculate exactly where each one belongs on the bell curve?

[@victor_peral]

Multiply the z score value by the standard deviation it gives the exact value from the mean

[@CloudGOML]

Salman Khan is KINGGGGGG

[@johnydoe9167]

bro it sounds like Scott Cawthon's voice acting before fnaf