Sampling distribution of the sample mean | Probability and Statistics | Khan Academy

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  • เผยแพร่เมื่อ 8 ธ.ค. 2024

ความคิดเห็น • 114

  • @jiusan
    @jiusan 11 ปีที่แล้ว +537

    watching these at 5AM the morning of your statistics midterm at university is the best

  • @peterbryan3971
    @peterbryan3971 6 ปีที่แล้ว +83

    You have been saving lives for the last 8 years, Keep doing like this!

  • @enemroy
    @enemroy 8 ปีที่แล้ว +59

    Love this Khan guy he breaks it down so well.

  • @vivspring
    @vivspring 13 ปีที่แล้ว +15

    thank you :) a slow student like me needs a patient tutor like you. thanks for helping me to understand

  • @applepicker4117
    @applepicker4117 10 ปีที่แล้ว +42

    finally, a video about this that makes sense!

    • @JeanPaulUS
      @JeanPaulUS 9 ปีที่แล้ว

      Apple Picker I know, right!

  • @mostinho7
    @mostinho7 2 ปีที่แล้ว +5

    Sampling distribution of the sample mean.
    Sampling distribution: sampled from a probability distribution (that we typically don’t know)
    Sample mean: each sample we take consists of n data points and we take the mean of them.
    We plot all the means of samples we took, each sample with n data points
    Take sample with n data points, find mean of sample, plot it.
    The plot of sample means will be more normal as long as n the number of data points in each sample gets larger, having less skew and kurtosis (measure how normal our distribution is, skew is being shifted left or right and kurtosis is how pointy it is)

  • @elahehnahvi5393
    @elahehnahvi5393 2 ปีที่แล้ว +6

    After 20 years of absence of study, just learning data science asynchronously, your videos are very helpful. thanks

  • @midknight198
    @midknight198 4 ปีที่แล้ว +7

    10 years later and it's still relevant and helpful

  • @brnjnsvld
    @brnjnsvld 10 ปีที่แล้ว +83

    "Skew is where there's few"

    • @elise3617
      @elise3617 4 ปีที่แล้ว

      wow tbh thank you

    • @SimplyAndy
      @SimplyAndy 3 ปีที่แล้ว

      wow now I understand it...

  • @a1kiwigirl
    @a1kiwigirl 13 ปีที่แล้ว +2

    Thanks, it was nice to have a break from reading, yet not feel guilty about procrastinating.

  • @judyzhu6698
    @judyzhu6698 3 ปีที่แล้ว +2

    Love how enthusiastic you are when teaching us

  • @w.t.h4115
    @w.t.h4115 10 ปีที่แล้ว +3

    At 7:25, positive kurtosis should not look like that. it's tail should lower than normal on both side.
    The peak of negative kurtosis should not taller than normal.

  • @ankitprasaddevrari4160
    @ankitprasaddevrari4160 7 ปีที่แล้ว +19

    drinking game...drink when he says sample

  • @halima2953
    @halima2953 4 ปีที่แล้ว

    Guess what! You're the best for me so far! Thank you so much

  • @Nughug
    @Nughug 14 ปีที่แล้ว +3

    THANK YOU SO MUCH!

  • @jinbochen9623
    @jinbochen9623 3 ปีที่แล้ว +1

    2021er here. Thank u

  • @aishnaarora1336
    @aishnaarora1336 4 ปีที่แล้ว

    you are a blessing Sal Khan!

  • @priyaann9007
    @priyaann9007 4 ปีที่แล้ว

    10 years old yet good video.

  • @carrd1
    @carrd1 6 ปีที่แล้ว +1

    Thank you for all of your videos! They are so helpful!!!!

  • @sarahaghani2252
    @sarahaghani2252 7 ปีที่แล้ว +1

    Thank you so much Sal

  • @nanochan1168
    @nanochan1168 8 ปีที่แล้ว +1

    Thank you ALOT😭😭..I was completely lost before this video

  • @thatguyadarsh
    @thatguyadarsh 3 ปีที่แล้ว

    so very much informative and intuitive. Thank You

  • @ev1836
    @ev1836 5 ปีที่แล้ว

    this guy saves lives

  • @cococake0315
    @cococake0315 13 ปีที่แล้ว +1

    Thanks!I FINALLY understood!!

  • @rjeption
    @rjeption 2 ปีที่แล้ว +2

    So larger sample sizes would provide more accurate distributions

  • @AJ-et3vf
    @AJ-et3vf 2 ปีที่แล้ว

    awesome video! THank you!

  • @abhayraj3568
    @abhayraj3568 ปีที่แล้ว

    So well explained.

  • @KimSaastamoinen
    @KimSaastamoinen 3 ปีที่แล้ว +2

    Thanks for the video! Might be stupid question but shouldn’t the sample size be noted as ”Sample n” instead of ”Sample N” on the CLT test tool?

  • @Fatcrazypanda
    @Fatcrazypanda 4 ปีที่แล้ว

    Thank you 🙏

  • @tanimowosunkanmi4028
    @tanimowosunkanmi4028 6 หลายเดือนก่อน

    You are amazing!

  • @yaboiperson9512
    @yaboiperson9512 3 ปีที่แล้ว +1

    I don't even understand what's going on but nice vid!

  • @sonamnaik2804
    @sonamnaik2804 5 ปีที่แล้ว

    ty💙

  • @harountrabelsi3412
    @harountrabelsi3412 5 ปีที่แล้ว +1

    If only my professors were half as good as you

  • @1337bitcoin
    @1337bitcoin 14 ปีที่แล้ว

    Thanks so muchthese are great videos

  • @meriemeennajah7459
    @meriemeennajah7459 ปีที่แล้ว

    Thank you so much

  • @manudewi
    @manudewi 2 ปีที่แล้ว +1

    @Khan Academy can you please clarify for me th following doubt.
    I got confused at 4:11 when you say ."And so when I click animated, what it's going to do is it's going to take FIVE SAMPLES FROM from this probability distribution function..."
    And you keep repeating in the video that it taes 5 samples....
    shouldn't it be." And so when I click animated, what it's going to do is it's going to take ONE SAMPLE OF SIZE FIVE from this probability distribution function..."
    I'd appreciate some help on this. Just thought I understood the topic and then I hear the video's author talking about "taking five samples".

  • @맛있는수박토마토
    @맛있는수박토마토 หลายเดือนก่อน

    I am here in 2024 to study the sampling distribution of the sample mean. I came because I thought I was the only one who found it challenging.

  • @Rosie-bi5gz
    @Rosie-bi5gz 6 ปีที่แล้ว

    I love khan academy

  • @jakeweston5898
    @jakeweston5898 ปีที่แล้ว

    cheers mr khan

  • @fonty8433
    @fonty8433 ปีที่แล้ว

    yall gotta get bro a new mic

  • @rai7323
    @rai7323 ปีที่แล้ว

    Bravo!

  • @priyak2303
    @priyak2303 5 ปีที่แล้ว

    You explain so well😍

  • @SinaImani1
    @SinaImani1 14 ปีที่แล้ว

    outstanding!

  • @jimmybro001
    @jimmybro001 13 ปีที่แล้ว

    Thanks

  • @jonathangordon5234
    @jonathangordon5234 7 ปีที่แล้ว +2

    How difficult is the proof for the CLT? What level of math is needed to follow it?

    • @davidjohnson-my6sr
      @davidjohnson-my6sr 7 ปีที่แล้ว

      Jonathan Gordon literally search it up and judge it for yourself brainlet. with you asking that question, probably more knowledge than you will have within the next 5 years, and our district learnt it in the last year of hs

  • @bakhodiryakubov3981
    @bakhodiryakubov3981 4 ปีที่แล้ว

    does it pick certain number more/less often from the first graph, depending on the probability of the distribution?

  • @alilalani9531
    @alilalani9531 4 ปีที่แล้ว

    MIDTERM TOMORROW!

  • @graceyudha
    @graceyudha 4 ปีที่แล้ว

    i think he know everything about everything. he's basically god

  • @Lionpolo
    @Lionpolo 8 ปีที่แล้ว +5

    Wow
    I literally calculated the area of universe at a particular time by this methodology

    • @ishansrt
      @ishansrt 7 ปีที่แล้ว

      how can you do that? the universe is 3d for an average guy who doesn't know relativity

    • @blahbleh5671
      @blahbleh5671 6 ปีที่แล้ว +2

      you lying poo

    • @victor_peral
      @victor_peral 3 ปีที่แล้ว

      That’s calculating the area of a sphere , you should get a Nobel price for lies

  • @dk.scholar4506
    @dk.scholar4506 8 ปีที่แล้ว

    please, can any one tell me how like these videos manufactured ??

  • @michal234486
    @michal234486 7 ปีที่แล้ว +1

    when comparing N=5 and N=25 I think you should look at the ratio kurtosis/sd (or sth like that) to infer about how close to the normal we are (?)

    • @victor_peral
      @victor_peral 3 ปีที่แล้ว

      Perhaps the skew and kurtosis are better indicators for inference , it’s relation to standard deviation might be just for logical purpose I’m guessing

  • @iamb2348
    @iamb2348 9 ปีที่แล้ว

    For the negative kurtosis example are the tails supposed to reach zero? Shouldnt they go on to infinity like the normal distribution and positive kurtosis?

    • @victor_peral
      @victor_peral 3 ปีที่แล้ว

      Kurtosis is basically concerned about the shape of the peak of the frequency distribution, but ideally a thin tail can lead to a less pointy peak , that tail starts from infinity to infinity

    • @iamb2348
      @iamb2348 3 ปีที่แล้ว

      @@victor_peral Thanks for bringing back my nightmares of university exams :D

    • @victor_peral
      @victor_peral 3 ปีที่แล้ว

      @@iamb2348 can’t believe I replied from 6 years back 🤣😂

  • @mitchellvanvugt8587
    @mitchellvanvugt8587 7 ปีที่แล้ว

    sampleception

  • @corradoblondi9792
    @corradoblondi9792 3 ปีที่แล้ว

    nice

  • @yogabagaba93
    @yogabagaba93 12 ปีที่แล้ว

    nice drawings 7.29

  • @artistiaay5512
    @artistiaay5512 5 ปีที่แล้ว

    Whats the difference between median and mean?!

    • @SuperYtc1
      @SuperYtc1 5 ปีที่แล้ว +1

      Median is when you got someone called Ian who is medical. Mean is when you are nasty to someone.

  • @vsimoul
    @vsimoul 15 ปีที่แล้ว

    very bice thank you

    • @teluguinfoin
      @teluguinfoin 9 หลายเดือนก่อน

      😮😮you're the first onee

  • @ramborambo3456
    @ramborambo3456 5 ปีที่แล้ว

    can anyone suggest some books

  • @rickmonarch4552
    @rickmonarch4552 4 ปีที่แล้ว

    But we used here only one random variable. I kinda find it weird. So I guess if it works for one with the given exp.val. and variance then we just add the outputs and still get the normal distribution?

  • @imranali-iy5wk
    @imranali-iy5wk 7 ปีที่แล้ว

    How to make samples in case of without replacement with size 4 can you know any trick please tell me

  • @yogabagaba93
    @yogabagaba93 12 ปีที่แล้ว

    she's so great!

  • @TimCsbE
    @TimCsbE 12 ปีที่แล้ว +1

    KHAAAAAAAAAAAAAAAAAAAAAAAAN

  • @raghu_yadav_yt
    @raghu_yadav_yt 8 หลายเดือนก่อน

    👍👍👍

  • @victorserras
    @victorserras 7 ปีที่แล้ว

    He gets 5 samples and then averages them. What is the size of the original samples? 5 as well?

    • @victor_peral
      @victor_peral 3 ปีที่แล้ว

      The same size is 5 , he just took 5 sampling to illustrate he latter did 1000 sampling of the sample size of 5 and ploted the frequency distribution of mean of each of the 1000 sampling

  • @wolfgangi
    @wolfgangi 6 ปีที่แล้ว

    how can God not exist when everything works so beautifully in math and statistics

  • @palui
    @palui 14 ปีที่แล้ว

    It seems to me one needs to be sampling from a non pre-existing, infinite population in order for the CLT to work. For example, the generation of random variables from a population would need to come from something like a rolling of a die where there is no population "size" existing in advance. If the population had a size, like a population of people, then as n approached infinity, it would reach N and the distribution of the means would be a single value. Yes?

  • @dajohnman57
    @dajohnman57 14 ปีที่แล้ว +1

    skews are poopy like tails

  • @redberries8039
    @redberries8039 7 ปีที่แล้ว

    seems to me that a large enough sample size [or the cumulative results of many samples] if plotted would mirror the shape of the original data set ...the values would be different, but the relative frequencies at each position would be the same ...that's right isn't it?

    • @blahbleh5671
      @blahbleh5671 6 ปีที่แล้ว

      no

    • @victor_peral
      @victor_peral 3 ปีที่แล้ว

      Not exactly bro , the shape of the sample size will differ from the frequency of mean of samplings taken , we are more concerned that the distribution will look like a normal distribution as the size increase , but the mean of the frequency distribution will be close to the mean of the sample size

  • @jessicakraemer2091
    @jessicakraemer2091 4 ปีที่แล้ว

    This frickin class is skewed down👎. I HATE STATISTICS!!!!