Normal Distribution & Z-scores

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  • čas přidán 5. 09. 2024
  • This video shows how to calculate "inside areas" and "areas in the extreme" in a normal distribution using Z-scores. This video can also be found on my website statstutor.book...

Komentáře • 615

  • @TheBigFella
    @TheBigFella Před 9 lety +339

    thanks for taking the time to put this together - guys like you make the world a better place by freely making education available to the masses for free - you rule!

    • @LFSPharaoh
      @LFSPharaoh Před 7 lety +3

      overpriced academia be like "THEY TOOK OUR JOBS!"

    • @masoomaaslam2613
      @masoomaaslam2613 Před 6 lety +2

      Oisin Hughes stay blessed

    • @user-fg3mi3vk1s
      @user-fg3mi3vk1s Před 6 lety +1

      Oisin Hughes
      Thank you very much.
      My form teacher are perfectly in knowledge however he doesn't know how to teach ,under his teaching the students cannot really understanding what is real normal distribution and only on remember the fix formula.
      If you remember the formula you get the score
      If you don't,you can't pass the exam.
      That was why most of the our class had failed this subject years ago.NOT on understand but on memory

    • @user-fg3mi3vk1s
      @user-fg3mi3vk1s Před 6 lety +1

      Oisin Hughes this had shows the difference way on the teaching.
      Instead of memory teaching.make students understand are more helpful.Thanks you again

    • @PhysicsThroughComputation
      @PhysicsThroughComputation Před 4 lety

      czcams.com/video/029laWCUOj4/video.html

  • @MissWooHoo11
    @MissWooHoo11 Před 10 lety +113

    I love how you did it multiple times. Its 1 million times better than other vids when they just show you once. This really gets it through your head.

    • @supiriorthinker9580
      @supiriorthinker9580 Před 10 lety

      your head! It like most degrees are apparent to me before doing them!

  • @Freacoolize
    @Freacoolize Před 8 lety +947

    whos here for tomorrow's exam

  • @BobotheDoritoBandit
    @BobotheDoritoBandit Před 8 lety +105

    this is honestly what I look for in a online math video , no rambling... you nailed it.

  • @MoyoTaiwo
    @MoyoTaiwo Před 8 lety +45

    After hours of laboring, and countless youtube videos, I finally got one that broke it down in bits and pieces. For one who is coming from a not too sound mathematical background, this video has been a life saver in understanding normal distributions.
    I'll now go ahead and tackle probability with this new found knowledge.
    Muchos gracias!!!

  • @bushybrovvs
    @bushybrovvs Před 7 lety +8

    For those of you who have different charts, you're suppose to subtract the z-scores from one another instead of adding them like he does. For example, with the second problem: If you look at your chart and get .02275 for -2.00, and .97725 for 2.00; SUBTRACT them. When you subtract .02278 - .97725, you get 95.45. It isn't 95.44 but its close enough...
    I did the same thing with the first problem. I got z-scores .15866 for -1.00 and .84134 for 1.00. When I properly subtracted them, I got 68.26.

    • @kadyr8935
      @kadyr8935 Před 7 lety

      Thank you so VERY much for this comment! I was going crazy trying to figure out why I couldn't get the same answer!!

  • @xGoldenArrow
    @xGoldenArrow Před 9 lety +229

    Way easier to understand than my stats prof

  • @victorfernandes7955
    @victorfernandes7955 Před 9 lety +9

    Straight forward, simple, no unneeded explanations. Just what I was looking for. Thank You

  • @kevin71794
    @kevin71794 Před 8 lety +2

    so much clearer and easier to understand than coming from an old PhD professor....and the book. needless to say what i spent hours trying to comprehend I easily learned by watching this video twice. No bs. straight to the point. How teaching should be.

  • @zeroc977
    @zeroc977 Před 8 lety +2

    My teacher was explaining this to the class for around 2 classes and most of us didnt get it. This video is the best!

  • @fgestosani
    @fgestosani Před 12 lety

    Thanks for not talking too much and making it sound so easy/simple!!!

  • @KH-iq7qo
    @KH-iq7qo Před 7 lety +1

    Thank you! This makes so much sense. My book made is seem like greek! Please post all of your teachings! Teachers like you make the world a better place.

  • @wangxingyu575
    @wangxingyu575 Před 8 lety +2

    clear as hell, i was doing CFA level 1 test and struggling with normal distribution! your lecture is amazing.. it helps a lot, thx buddy

  • @sharynmain2432
    @sharynmain2432 Před rokem

    Thank you so much for keeping this video concise, simply and straightforward. The hours I have invested in this week only, by being at Uni have tested my sanity in regards to normal distribution. It is now getting synthesise in my being slowly but surely. My lecturer, oddly enough commented on how many tabs I had on my laptop when helping me with something , little does she know I have spent about an hour and a half just searching through videos on this subject….I wish I had found this earlier . It just shows you the algorithm is truly watching your moves…. Just think about that for a moment. Thanks again for your generosity.

  • @MrSafa61
    @MrSafa61 Před 6 lety

    Seven years later, a random Turk from the Netherlands comes by, learns what the system didn't want to provide, or assumed we already knew, and leaves again. Thank you for putting this here. Out of all the videos out there, only yours helped me out.

  • @zuzol735
    @zuzol735 Před 5 lety +1

    I was in a 3 hour lecture at uni not being able to understand it at all and you explained it in 10 minutes.... impressive ! Thank you so much.

  • @Jordi_Plays
    @Jordi_Plays Před 9 lety +36

    This is a miracle. I didn't get this until I watched your video and my final is tomorrow morning. XD thanks for sharing!

    • @soliderarmatang5664
      @soliderarmatang5664 Před 9 lety +5

      how did your final go?

    • @Naamy19X9
      @Naamy19X9 Před 8 lety

      +Moonfall Hey as someone who has written a final on this, can you please explain the last example? He spoke about a standard rule and 3 standard deviations...what is that all about?

    • @Gealamusic
      @Gealamusic Před 3 lety

      I'm in the exact same position, 6 years later XD

  • @papag3324
    @papag3324 Před 9 lety +1

    Just wanted to say thank you! I'm in beginners Stats class and could not figure a certain problem out...random person scoring above 65%. Your instruction on IQ of greater than 130% helped me out! Thanks again!!

  • @nc7182
    @nc7182 Před 6 lety +1

    I have my first math exam in two years tmrw and doing the textbook problems had me so stumped. I'm solving these with you and pausing so I can test myself and beat you to the next step. I'm nailing all these and feeling way more confident about not only solving the problems but also about the logic behind it all. Thanks so much for this great video :)

  • @Sumweight
    @Sumweight Před 8 lety +2

    You're a life saver! Been studying for final and was having issues until watching your video. THANK YOU.

  • @habiburrehman327
    @habiburrehman327 Před 5 lety

    you are genius...at least for for me .. you are between those very tiny percentage of people who can explain this in such a easy way ... God Bless

  • @miranda3093
    @miranda3093 Před 7 lety +1

    finals in about 2 hours and you made more sense in 10 mins than my lecturer in 3 months - thank youuu

  • @AllaahuAkbar60
    @AllaahuAkbar60 Před 9 lety +1

    This professor is so awesome that Majority of people can understand Z score calculations within 10 minutes :)

  • @xmediabox
    @xmediabox Před 10 lety +18

    Americans are the most Generous People on the planet top education for free.
    I never meet people like you here in Germany
    I love America.
    clear and very helpful

    • @NoraIsmailwins
      @NoraIsmailwins Před 10 lety +7

      Yes, our education system is awesome because we give financial aid to people that can't afford school :) Most of us are generous with knowledge too.

    • @BbyGLK
      @BbyGLK Před 9 lety +6

      supirior thinker how are u so rude to ppl when youtube name is spelled wrong? humble yourself and stop with the negativity

  • @BismillahArif
    @BismillahArif Před 9 lety

    The most easy and useful in all CZcams videos of normal distribution thank for easy explanation ready for exams now

  • @pistalo1
    @pistalo1 Před 10 lety +3

    thanks so much. learn more in this ten minutes than class for the last two weeks

  • @monicag.6462
    @monicag.6462 Před 6 lety

    Is it too much to ask for additional examples? This was BEYOND GREAT and something I haven't seen that goes straight to the point!

  • @Shabz1031
    @Shabz1031 Před 5 lety

    you made this so easy to understand in 10 minutes when my teacher spent 1 hour trying to figure out how she did it the first time... Thank you so much

  • @wargarblet3498
    @wargarblet3498 Před 10 lety

    My instructor is incredibly bad. He rambles, starts and stops at odd points, and generally makes no sense. He does a poor job of relating the information he's spewing out to what it actually represents, and to top it all off, he wrote his own text for the class which makes just as much sense. I had no idea how to do my homework. Class has been in session for almost a month.
    By 7:47 in this video, you've already managed to teach me more than he has thus far this semester. I can't thank you enough for posting this.

  • @TheMcginty222
    @TheMcginty222 Před 9 lety +1

    My poor head don't understand the concept yet , but after strolling dozens of videos , your video game high hopes , thank you , i like the steps you go through, my professor is like a hurricane !!

  • @mochalatte2965
    @mochalatte2965 Před 5 lety +1

    THANK YOU SO MUCH. I have a college class certification due in 4 days and this really helped me understand bell curves and standard deviation with percentages. You rock!

  • @ddigwell
    @ddigwell Před 6 lety

    LOVE how simple and to the point, you make this!

  • @Mentles1
    @Mentles1 Před 11 lety

    first person out of 10 I've seen to not fuck up the bell curve by allowing to touch the x-axis. good job

  • @angelburgos2921
    @angelburgos2921 Před 10 lety +10

    i finally understand how to apply the information from class. thank you so much

  • @Drcalvinklein
    @Drcalvinklein Před 6 lety

    you explained what my professor (who has a phd and whos been published dozens of times) could not. Sir, I tip my hat to you, and id like to buy you a beer (if your ever in the area). Many thanks.

  • @moviemaker667
    @moviemaker667 Před 6 lety +1

    This topic can be really difficult the first time learning them, but once it clicks (Which can take a while), it's not so bad. You seem to help it click a lot more quickly than it otherwise would!

  • @anonymous12726
    @anonymous12726 Před 8 lety

    you explain it very concisely and it's straight to the point. It's helped me tremendously. Thank you. I think, learning the symbols that correspond to this language are the hardest part when understanding this concept. Also, it's essential to understand the formula when solving these problems. My Professor didn't explain it so I understood it or didn't take the time. Your online video shows all this in an easy to understand format. Keep up the good work in helping people work through challenging concepts in an easy manner.

  • @smvsiyer
    @smvsiyer Před rokem

    Excellent. This example can be replicated in any set of scores - including employee performance , Ranking of companies in revenue performance, etc.

  • @brendaliz1989
    @brendaliz1989 Před 13 lety

    This was amazing. I finally get z scores. I love the fact that you went step by step and gave several examples. Nicely done

  • @meteoriter1647
    @meteoriter1647 Před 5 lety

    The percentage of dislikes to likes for this video at this moment is 234 out of 5.7K or 4.1% lying outside 2 standard deviations or 100 - 2 x 47.72 = 4.56% ! Meaning the dislikers are insignificant critics to this well-made video. Thanks pspollard1 !

  • @leam6371
    @leam6371 Před 6 lety +1

    Thank you so much! My final exam is in 30 mins and you’ve made this really clear for me!

  • @NoraIsmailwins
    @NoraIsmailwins Před 10 lety +6

    I like this explanation. It's simplified and dummy-friendly.

    • @GunjanSubedi
      @GunjanSubedi Před 10 lety +4

      supirior thinker, 1. plz correct your spelling first, .....2. when u feel urself superior and start to boast, u actually lose ur ability to learn more...there are still millions ideas to learn....and 3. ur bragging looks like u really learnt about "black-hole" at 15 becoz by then u started reaching adolescence...4. I learnt by heart an epic book >2000 pages "mahabharata" by 10, calculus by 8, steriochemistry by 12, Molecular medicine by 15, and completed my phd in 23.... !!! and still i am learning basic statistics becoz, i missed learning it since long !!! so fuck u !!

  • @MrJassu2
    @MrJassu2 Před 5 lety

    This has to be 1 of the best video out there on Zscore...thanks

  • @tubulartels
    @tubulartels Před 4 lety +1

    Excellent work. The only confusion might arise from calling the table data that you look up “distances” when they are actually the AREA under the curve. You do say area in the example where you have to subtract it from 0.5 to determine the “greater than” AREA. For those of you with the double data values, you4 chart is giving the area between the -x and +x value of the z score.. so it’s double the area.

    • @smvsiyer
      @smvsiyer Před rokem

      You are right. It is formally called "area under normal curve"

  • @annegelenb.7336
    @annegelenb.7336 Před 6 lety

    life saver thank you for this video because my teacher in statistics get mad on us then he told that he is going to have a quiz but he didnt discuss this very well

  • @lwc888
    @lwc888 Před 3 lety

    Thank you! You made it simple to understand. The CFA study guide made used 900 variables and made it so impossible to understand. Could have explained what the z score and z table mean in one sentence.

  • @madzo.e.mwadzoya
    @madzo.e.mwadzoya Před 7 lety

    my life was missing this information. Good work!!!

  • @cassandrarowe9098
    @cassandrarowe9098 Před 10 lety

    This has just saved me from failing stats due to having a terrible professor! Thank you so much for the video!

  • @Philaundre
    @Philaundre Před 4 lety

    Best video for Normal Distribution & Z-scores.. -Thank you for this!!!

  • @tiffanysarafian9739
    @tiffanysarafian9739 Před 3 lety

    thank you, this helped so much. i can not explain how glad i am i found this video

  • @thecop-arazzi653
    @thecop-arazzi653 Před 7 lety

    you are the first person I unstand. prof always keeps in algebraic form but idk what it stands for when u break it u take a hard problem make it simple

  • @Nebula-lr3ie
    @Nebula-lr3ie Před 3 lety

    I have an exam in 1 day and you literally saved me.

  • @livinlavi-donnisha7359
    @livinlavi-donnisha7359 Před 7 lety +2

    omg hes saved my life! i was freaking out about my exam coming up

  • @salimalsenani8169
    @salimalsenani8169 Před 7 lety

    i have an exam after 3 hours about this .. i am very thankful for u

  • @NINABURROUGHS123
    @NINABURROUGHS123 Před 8 lety

    Thank you so much for the most simplest breakdown ever!!!!!! I wish you taught at a college near by my residence. Thank you

  • @ColbyTheNisest
    @ColbyTheNisest Před 10 lety +1

    have a test tomorrow and this video just saved my life

  • @souleaterROX88
    @souleaterROX88 Před 8 lety

    I now feel that I may actually pass this unit. Thank you so much for taking the time to make this video.

  • @dr_pumper_dumper880
    @dr_pumper_dumper880 Před 7 lety

    You teach this soo much better than my teacher. She made it far to complicated and didn't explain it aswell as you did

  • @lulublu88
    @lulublu88 Před 8 lety

    Finally! an explanation that makes sense!. thank you so much! i've spent hours trying to figure this out and you did it in 10 minutes.

  • @annaschow9188
    @annaschow9188 Před 5 lety

    I know this video was uploaded literally 8 years ago, but now it all makes sense and I’m going to pass my standard

  • @Nunuvang
    @Nunuvang Před 11 lety +1

    Thank you sooooo much! This makes a lot more sense than it did in class.

  • @waelayari6593
    @waelayari6593 Před 5 lety

    You are a life savior Sir

  • @sergioalvarez8710
    @sergioalvarez8710 Před 8 lety +2

    This guy is so good and I'm learning this stuff in my sophomore year

  • @so0osa
    @so0osa Před 9 lety

    I can't believe it's that simple!!
    Thank you so much for making my life easier

  • @TheGeorge3011
    @TheGeorge3011 Před 10 lety +48

    How come the Z table I was given in class is different ? at 1.00 on my Z tableI have .8413

    • @ronanogales7247
      @ronanogales7247 Před 5 lety

      i got that allso that value but i did i the sci cal...not actually on z table

    • @AJRadaza
      @AJRadaza Před 5 lety +34

      It's because the area for the z in your table starts from -3.5 to 3.5. Not from 0 to 3.5.
      For your case, just subtract .5000 of the given cumulative area.
      Sorry for posting this 4 years after your comment.

    • @brendag331.
      @brendag331. Před 4 lety

      same

    • @aceroargentino1049
      @aceroargentino1049 Před 4 lety

      AJ Radaza lmaoooo 🤣🤣🤣🤣🤣

    • @rahmahdalhat8484
      @rahmahdalhat8484 Před 3 lety

      @@AJRadaza no thanks for posting this.I am having problems and this was helpful...but mine starts from _3.0

  • @rockentui
    @rockentui Před 12 lety

    @danpluso you're right! Another way I look at it now is instead of adding .3413 and .3413 we substract it! So because I use the "normal" table from my textbook, or "area from the left" table. The figures would be 0.8413 - 0.1587 and voila 68.26%. Thank you danpluso.

  • @jaimeetreloar5667
    @jaimeetreloar5667 Před 10 lety +1

    thank you so much. this video has helped me heaps. i didnt understand this at all until i watched this. great information

  • @Stanger1252
    @Stanger1252 Před 10 lety

    Thank you sir! I was trying to learn this from the text for the last hour.. you made it so much easier!!

  • @syl860
    @syl860 Před 5 lety +3

    thank you bro! i need this tomorrow for my exams

  • @heya9302
    @heya9302 Před 8 lety

    OMG THIS IS GOOD THANK YOU FOR SAVING ME OF MY SCREWED UP LIFE. MY EXAM IS IN LESS THAN 12 HOURS

  • @zoehowell5589
    @zoehowell5589 Před 10 lety +1

    This helped refreshed my memory! Have a final tomorrow

  • @uruminati5382
    @uruminati5382 Před 8 lety

    This video is absolute genius! Thanks so much, you made it just so easy to understand

  • @lb1367
    @lb1367 Před 7 lety

    Perfect! Straight to point explanation. My Professor just reads off a PowerPoint!

  • @yasharanathaniel9291
    @yasharanathaniel9291 Před 9 lety +1

    Finally understood how this works!!! THANK YOU SO MUCH!

  • @klausbyronentico6531
    @klausbyronentico6531 Před 4 lety

    The effort of having examples helps a lot

  • @PrasangaMadhusanka
    @PrasangaMadhusanka Před 12 lety

    This is excellent video..i got full of knowledge about normal distribution through this video..
    thank you very much

  • @taransingh3297
    @taransingh3297 Před 6 lety

    I search lots of videos but finally I got it ...thank u. So muchhhh

  • @florianrey881
    @florianrey881 Před 3 lety

    Thank you very much for your explanation! It helped me a lot to understand better the normal distribution!

  • @etch.asketch2420
    @etch.asketch2420 Před 7 lety

    Great tutorial. This really helped me to understand normal distribution and z graphs.

  • @jamessaldua730
    @jamessaldua730 Před 3 lety

    When my teacher introduced this topic I got overwhelmed by the name, goos thing she linked your video to the classroom.

  • @ablimitablez6530
    @ablimitablez6530 Před 8 lety +1

    Hello ! I've just watched many videos about standard deviation and couldn't understand what exactly it was. But after watching your video, within three minutes, i totally understand what the standard deviation really is. Your video really worked for me to understand it, Thanks !

  • @JosephStJohn-cc7uk
    @JosephStJohn-cc7uk Před 12 lety

    Thank you so much. Failed statistics. Must now help my daughter. I now understand z scores. You might just help her pass!

  • @gracepowell311
    @gracepowell311 Před rokem

    Thank god for you. I fully appreciate the clarity.

  • @kurbennnm3404
    @kurbennnm3404 Před 8 lety +2

    Bless your soul Man, you just saved me

  • @NightsareStarry
    @NightsareStarry Před 12 lety

    Thank you so much :) I realized I should thank each video that teach well. You are one of them, Mister! Keep going :)

  • @dan576-b9f
    @dan576-b9f Před 8 lety +2

    Thankyou for the video, it really helped to how this precisely and clearly

  • @niveshsimon699
    @niveshsimon699 Před 7 lety

    Love this you explain nice and simply that it looks so easy to understand now...Thanks mate

  • @shellymorgan1159
    @shellymorgan1159 Před 4 lety

    Thank you so so much!!!! This is the best video I have seen so far!

  • @VIPAgnieszka
    @VIPAgnieszka Před 12 lety

    Very nicely presented - it`s all much clearer for me now - thank you!!!!

  • @Shavi99r
    @Shavi99r Před 9 lety

    Thanks a lot
    after watching this video I get rid of my confusions regarding normal distribution

  • @cass733
    @cass733 Před 6 lety

    thank you for this ... short & straight to the point

  • @gazellerose2584
    @gazellerose2584 Před 5 lety

    BEST EXPLANATION OF THIS TOPIC! THANK YOU SO MUCH

  • @nawal7671
    @nawal7671 Před 3 lety

    Thank you so much it is very easy to understand normal distribution after your explanation 🙏

  • @emichh4
    @emichh4 Před 12 lety

    wow you helped me so much. so explain everything so clear and went step by step. thanks!

  • @danpluso
    @danpluso Před 12 lety

    @rockentui You may be getting confused by the two different chart versions like I myself was a few days ago. It seems like the most common chart used in classes is the "Area from the left" chart while this video is using the "Area from the mean" chart. Add a .5 to the last value on his chart (Z=3.9) and you will get the .9990 that is on the "Area to the left" chart.

  • @starrfiddler
    @starrfiddler Před 12 lety

    Studying for the FE. Thanks for your video!

  • @jazminegipson6934
    @jazminegipson6934 Před 5 lety

    this video was so helpful! thanks for doing multiple examples with different problems!!

  • @Jasmine13096
    @Jasmine13096 Před 8 lety

    This video has really helped me. Thank you for putting it up.

  • @Jenigami
    @Jenigami Před 7 lety +2

    Thank you for explaining this so clearly!

  • @kelly_browning
    @kelly_browning Před 5 lety +1

    Really great explanation. I wish I would've seen this video before I crashed and burned on my test :/ But thanks for putting this up. Super helpful!