Chi Square Distribution Test of a Single Variance or Standard Deviation

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  • Опубликовано: 11 сен 2024
  • This statistics video tutorial provides a basic introduction of the chi square distribution test of a single variance or standard deviation. It explains how to use it in order to determine whether or not you reject the null hypothesis.
    Confidence Intervals & Margin of Error:
    • How To Find The Z Scor...
    Find The Z-Score Given Confidence Interval:
    • How To Find The Z Scor...
    Student's T-Distribution:
    • Student's T Distributi...
    Hypothesis Testing - Null & Alternative:
    • Hypothesis Testing - N...
    Type I and Type II Errors:
    • How To Identify Type I...
    One Tailed and Two Tailed Tests:
    • One Tailed and Two Tai...
    _______________________________________
    Test Static For Means & Pop Proportions:
    • Test Statistic For Mea...
    Hypothesis Testing Problems:
    • Hypothesis Testing Pro...
    P-Value Method - Hypothesis Testing:
    • P-Value Method For Hyp...
    Hypothesis Testing - Proportions:
    • Hypothesis Testing - S...
    Difference of 2 Means - H Testing:
    • Hypothesis Testing - D...
    Cohen's D - Pooled Standard Deviation:
    • How to find Cohen's D ...
    Hypothesis Testing - 2 Proportions:
    • Hypothesis Testing Wit...
    __________________________________
    Matched or Paired Samples t-Test:
    • Matched or Paired Samp...
    Chi Square Test:
    • Chi Square Test
    Chi Square Distribution Test:
    • Chi Square Distributio...
    Test of Independence - Chi Square Dist:
    • Test of Independence U...
    Final Exams and Video Playlists:
    www.video-tuto...
    Full-Length Videos and Worksheets:
    / collections

Комментарии • 57

  • @TheOrganicChemistryTutor
    @TheOrganicChemistryTutor  Год назад +1

    Next Video: ruclips.net/video/y5nxiL6civU/видео.html
    Final Exams and Video Playlists: www.video-tutor.net/
    Full-Length Math & Science Videos: www.patreon.com/mathsciencetutor/collections

  • @_M_D_M_
    @_M_D_M_ 3 года назад +26

    Excellent. One suggestion, please rename your video to explicitly say it is a Left Tail Chi-Square test. We don't have many videos on RUclips solving this problem. It will be very easy to search. I reached here after 7-8 unwanted videos. Thanks.

  • @virgojake4531
    @virgojake4531 Месяц назад +3

    I've got a Statistics exam for my Finance degree tmr guys. Wish me luck

  • @samuelolonana-rt7mi
    @samuelolonana-rt7mi 6 месяцев назад +1

    What a nice one ... I like the way he tackle the question ... Is very easy than the way our lecturer taught us 😂

  • @PunmasterSTP
    @PunmasterSTP 3 месяца назад

    Chi square distribution? More like "Super video; thanks for the information!" 👍

  • @tylersoltmannowski3680
    @tylersoltmannowski3680 3 года назад +13

    My friend, the most relevant points that are crucial for your procedure are skipped. It will help your viewers when you step deeper into the mathematical details.

  • @prettyboi_gabriel
    @prettyboi_gabriel Год назад +1

    Thank you so much, this is really helpful. God Bless You👐

  • @Henqi
    @Henqi 3 года назад +2

    Excellent quality content, thank you!

  • @unknownn1073
    @unknownn1073 2 года назад +2

    What if your degrees of freedom is not on the table, how do we know what dof to choose from, for example if it’s in between of two, how do we know which one to choose?

    • @killthedark7283
      @killthedark7283 2 года назад +1

      degree of freedom is n-1, in this case, is df=20-1=19. If you have 10000 samples,then 10000-1=9999.

  • @BamaneGerald
    @BamaneGerald 3 месяца назад +1

    some clarity,when reading from chi square table, which figure do we use 0.05 or 0.95 because in the first example we used 0.05

    • @sserwaddaderrick1523
      @sserwaddaderrick1523 3 месяца назад

      We read the area to the right !! In the first example it was 0.05
      In the second it’s 0.95 coz the alternative hypothesis changes to < it’s skewed to the left

    • @sserwaddaderrick1523
      @sserwaddaderrick1523 3 месяца назад

      We read the area to the right !! In the first example it was 0.05
      In the second it’s 0.95 coz the alternative hypothesis changes to < it’s skewed to the left

    • @BamaneGerald
      @BamaneGerald 3 месяца назад

      thanks bro,but I ask for more highlights it really challenges when when it comes to whether we use 5% or 95%,,,​@@sserwaddaderrick1523

  • @abhishek90101
    @abhishek90101 3 года назад +4

    in this question we have the population sd(standard deviation) as well as sample sd so why are we not doing the Z test?

    • @The-cyber-imbiber
      @The-cyber-imbiber 3 года назад +4

      Chi square is correct because variance is not normally distributed (since it cant be less that zero)

    • @--ShivaS
      @--ShivaS 2 года назад +3

      T test and Z test follows normal distribution , whereas chi square test can be done for non symmetric distributions .

  • @dawnjane
    @dawnjane 9 месяцев назад +1

    I love this video, it was really helpful but is it possible to get examples where a right-tailed and two-tailed test is used? Also, I know that when getting that in this video the critical chi-square value is 10.117 but what's the reason we don't use the intersecting value between the alpha value and degree of freedom? Cause I've seen some articles that say you use the intersecting value between the alpha value and degree of freedom but then don't actually use it, instead they use AR to sort of substitute the alpha value in a chi-square distribution table.

    • @BamaneGerald
      @BamaneGerald 3 месяца назад

      actually am kinda confused too,and when you use alpha you get a different value

  • @user-zq7db7rf6g
    @user-zq7db7rf6g 26 дней назад

    i just want to confirm how do you assign your Ho and H1 conditions, which logic is used to assign Ho to that corresponding condition

  • @horiix7868
    @horiix7868 4 года назад +6

    what subject is this ?

  • @yeldossholtan
    @yeldossholtan Год назад

    I'm new to this subject, but i can't follow formula's logic here. Consider that professor sampled 1000 tests and got 6.9 std. More samples means more significance, so i would believe std is around 6.9. But chi square value would be very big, so we don't reject null hypothesis?? I'm so confused

  • @TheMetalalien
    @TheMetalalien 4 года назад +4

    I have a quesion : how do you decide how big the rejection area is?

    • @wintersolstice4250
      @wintersolstice4250 4 года назад +1

      I'm wondering that too unless he forgot to add it into the problem...

    • @Xcalzibur
      @Xcalzibur 4 года назад +8

      Generally it is something given within the problem, if not then you can assume it's 0.05 / 0.95 because that's a typical value used

    • @loureenvillarosa223
      @loureenvillarosa223 Год назад

      you can find it using 1- alpha

    • @dawnjane
      @dawnjane 9 месяцев назад

      not really sure if this is helpful right now but if you're given the level of confidence instead of the level of significance then you can get the value of the rejection region by using: 1 - level of confidence = rejection region.

    • @dawnjane
      @dawnjane 9 месяцев назад

      also, from my understanding, the critical value is the rejection region

  • @laurenadams474
    @laurenadams474 Год назад

    so much better than my professor

  • @Dlowr7
    @Dlowr7 2 года назад

    I have to make a chi square for my biology lab on our plant growth experiment of green beans in different types of soil. I don't understand where to start. How would I know what expected values for green bean growth are? It doesn't make any sense.

  • @tush89
    @tush89 Год назад +1

    What if hypothesis is two tailed?
    Then what will be the alpha?

    • @rradical4714
      @rradical4714 Год назад +1

      that is my question too, wont it be half alpha?

    • @russellkemmit8476
      @russellkemmit8476 Год назад +1

      @@rradical4714 2.5 on the left and right

  • @drismail469
    @drismail469 4 месяца назад

    Thank you şair but can you explain why variance is square SD

  • @darspiok
    @darspiok 3 года назад +3

    why do you sometimes square the sample​ variance and other times you dont?

    • @amiefelisha7633
      @amiefelisha7633 3 года назад

      in my own opinion, I just square the sample variance when it has only one tailed but if it is two tailed I don't. I hope it helps

  • @yingee8034
    @yingee8034 4 года назад +3

    why are we dealing with variance pls

    • @PunmasterSTP
      @PunmasterSTP 3 месяца назад

      Why not? It's just what this particular example asked for, and I have seen stats questions like it before.

  • @sithembilemthimkhulu6229
    @sithembilemthimkhulu6229 2 года назад +1

    Sir i find it diffult to understand isn't our altetnative hypothesis negative since it's less??

    • @finotips
      @finotips 6 месяцев назад +1

      here number cant be negative as it bounded by zero since log normal distribution

  • @laurenadams474
    @laurenadams474 Год назад +1

    king

  • @laurenadams474
    @laurenadams474 Год назад +1

    goated so goated

  • @samuraigolfer6919
    @samuraigolfer6919 3 года назад +1

    But why.

  • @fatimahilyas6433
    @fatimahilyas6433 2 года назад

    How do you know when the null hypothesis rejected...sometime less than critical value but sometime greater....?

    • @jinnjinn5567
      @jinnjinn5567 2 года назад

      left-tail test if Ha < x (to left of z-critical is rejection region) H₀ ≥ x
      right-tail test if Ha > x (to right of z-critical is rejection region) H₀ ≤ x
      two-tail test if Ha ≠ x (left of lower z-critical or right of higher z-critical is rejection region) H₀ = x

    • @jinnjinn5567
      @jinnjinn5567 2 года назад

      or in this case, just replace z with calculated chi value

  • @kailashks901
    @kailashks901 3 года назад

    6.9... nice

  • @evansnyman6729
    @evansnyman6729 4 месяца назад

    Thank you for the informative videos, but PLEASE, as a maths teacher, say your decimal fractions correctly! 12.23 is "Twelve point two three" and NOT "twelve point twenty three"!!!!! Or how would you express 12.023 for example? PLEASE!

    • @BamaneGerald
      @BamaneGerald 3 месяца назад

      but the critical value is 30.14,and so we reject the null hypothesis

  • @abands5082
    @abands5082 4 года назад

    Is the rejection value always .05 and .95

    • @Xcalzibur
      @Xcalzibur 4 года назад +1

      It can be anything, but a typical value is .05/.95

    • @tomatrix7525
      @tomatrix7525 4 года назад +1

      Nope! JG seems to use that value alot though. It can technically be anything, but we generally see 90% and up.

    • @Mushgid133
      @Mushgid133 Год назад +1

      @@Xcalzibur But how has the Critical Value been derived- on 0.95 or 0.005?? I thought it 95% will produce 30.14 critical value while 5% Significant Level will provide 10.11.

  • @ajjepriya2521
    @ajjepriya2521 2 года назад

    Question wasn't clarity to visible.. otherwise it's 👌...

  • @prashanttimalsina5462
    @prashanttimalsina5462 4 года назад

    .

  • @ig_sussybaka
    @ig_sussybaka 3 месяца назад

    saaar thoda thoda hinti aata