F-Test for two sample variances

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  • Опубликовано: 22 авг 2024
  • This video will show you how to verify if there is a difference in the variances of two samples. Basically, we are wondering if one sample is more varied than the other.

Комментарии • 47

  • @picsmics4
    @picsmics4 8 лет назад +105

    How is it that a free eight minute RUclips video accomplishes something that a week of lecture and an entire chapter of a three hundred dollar textbook couldn't...thank you,truly.

    • @fawadmahdi
      @fawadmahdi 7 лет назад +2

      Spot on

    • @zes3813
      @zes3813 5 лет назад +1

      no such thing as lecturx or accomx or not, lecture not lectured no matter what

    • @lameiraangelo
      @lameiraangelo 3 года назад +2

      5 years later and your statement is still true.
      10 years later and your statement will still be true.
      20 years later and your statement will still be true.

  • @Jlv271
    @Jlv271 8 лет назад +4

    You saved me on the first test!!! If only it would have been explained this simply in class!!

  • @WisdomPagesTV
    @WisdomPagesTV 8 лет назад +4

    Thank you very much! Excellent and complete explanation, I am grateful for the details mentioned at every step. You saved my life :)

  • @spoyledbratt
    @spoyledbratt 3 года назад

    Thank you. It's hard to find instructions online about how to find the F* critical value for 2-tailed tests. This video helps a lot.

  • @kelvinminor5889
    @kelvinminor5889 9 лет назад +13

    the critical value is 4.03 not 4.09

  • @rodrigosardinha3602
    @rodrigosardinha3602 6 лет назад +1

    I'm not a native speaker but you taught very well and clear, got it, thanks!

  • @ashutoshdas3010
    @ashutoshdas3010 6 лет назад +1

    Your video tutorials are great.

  • @vitokonte
    @vitokonte 10 лет назад +1

    Very well explained. Clear voice and concise content. The only thing I noticed is that you did not explain why the variance in two-tailed test should be highest on top and lowest on the bottom. Also why it was opposite for one-tail test. :)

  • @noueruz-zaman7894
    @noueruz-zaman7894 6 лет назад +2

    thank god ...by looking at the comment section i felt better
    i looked at my work-out book twice before acknowledging it must be a mistake ..critical value of the test is 4.03 not 4.09

  • @iam_a.maestro
    @iam_a.maestro 4 года назад

    being a teacher is the right career for you,kudos others are teachers but you wonder how the hell did they become teachers

  • @jimp2870
    @jimp2870 2 года назад

    I love your videos professor!

  • @nomanul12
    @nomanul12 10 лет назад

    I have got my quiz tomorrow and you saved me Taylor!! ^_^ Cheers . ..

    • @frankpeetershome
      @frankpeetershome 8 лет назад

      Nice video, thanks. One remark however. When comparing your test value to the critical value you are comparing the Ftest value to the Fcrit value. In your presentation you accidentally wrote Z values, which maybe confusing as the test is about the F distribution.

  • @mawliidmahmud9615
    @mawliidmahmud9615 9 лет назад

    thank so much for your outstanding explanations, simply remarkable

  • @bastiaanstultjens
    @bastiaanstultjens 3 года назад

    Thanks a million. This really helped!

  • @samvoisin3269
    @samvoisin3269 6 лет назад

    Thank you for submitting this video!

  • @tubuvegogoscholar4676
    @tubuvegogoscholar4676 4 года назад

    Thank you! Clear explanation.

  • @ashutoshbhardwaj4128
    @ashutoshbhardwaj4128 5 лет назад

    Nicely described

  • @1414gp
    @1414gp 8 лет назад +1

    what if degree of freedoms are differentr for two tailed test and then we have to find lower critical value

  • @abhishekmakam6699
    @abhishekmakam6699 7 лет назад

    I did using R and got this for the exercise problem.
    Can you please tell what is wrong?
    fcalc1

  • @videogrillo
    @videogrillo 6 лет назад

    you are the best

  • @SuperMixedd
    @SuperMixedd 5 лет назад

    but why would we need to know if one distribution has higher variance than the other? Could someone explain please?

  • @DeepakSharma-wz2fb
    @DeepakSharma-wz2fb 5 лет назад

    Thank you ma’am

  • @Sui_Generis0
    @Sui_Generis0 5 лет назад

    When you say choose the value that's closer, does that mean not to use infinity? So you dont use it even if the n's are > 1000

  • @sushodhan
    @sushodhan 6 лет назад

    How did you calculate significance as 0.05 ? Please help me out with this.

  • @sgtcojonez
    @sgtcojonez 6 лет назад

    I think the symbols that you are using for Population Variances are instead used for Population Standard Deviations. Right?

    • @samvoisin3269
      @samvoisin3269 6 лет назад

      sgtcojonez sigma squared is the symbol for population variance. Because the standard deviation is the square root of variance, the symbol for standard deviation is sigma.

  • @fysiologieee
    @fysiologieee 8 лет назад

    do you have to double the p value of an anova result because we use a two tailed F test ?

  • @mohdmuneer5075
    @mohdmuneer5075 7 лет назад

    thank u.

  • @xtzyshuadog
    @xtzyshuadog 5 лет назад

    What is s in that table of salt contents?

  • @jacobhero1577
    @jacobhero1577 4 года назад

    so i seem to be in a bit of a predicament- my alpha value is 0.1, what do i do to find my critical values?

    • @jacobhero1577
      @jacobhero1577 4 года назад

      nvm i found other f dist. tables

  • @MrCentripetal
    @MrCentripetal 9 лет назад

    thank you :)

  • @DrGP-lifestyle-MindBodySpirit
    @DrGP-lifestyle-MindBodySpirit 8 лет назад

    good

  • @ashutoshdas3010
    @ashutoshdas3010 6 лет назад

    Why do you use a comma instead of a dot or decimal point?

    • @zabba7461
      @zabba7461 4 года назад

      It's a European thing. She sounds Irish maybe

  • @ririssinambela5952
    @ririssinambela5952 9 лет назад

    thank you .......:)

  • @nobitatabino5959
    @nobitatabino5959 5 лет назад +2

    Good effort but this is WRONG.
    First and foremost, there is no such a thing as two-tailed test for Chi-Squared and F distribution. When mathematical transformation is being applied, both sides of the normal distribution curve has been already considered within the Chi-Squared and F distribution itself. As such, no negatives values are observable and there goes the symmetrical shape of the distribution.

  • @jayjayf9699
    @jayjayf9699 5 лет назад

    How did the critical value magically change from 4.03 to 4.09?

  • @Sats33
    @Sats33 5 лет назад

    I didn't understand.. Probably the method is different or approach is different but it is contradicting to what I've learnt.

  • @comfycozyarewe388
    @comfycozyarewe388 5 лет назад

    🥧

  • @ezekbardunsihk5735
    @ezekbardunsihk5735 3 года назад

    I hate statistics. So much