How To Calculate Sample Standard Deviation (Step By Step)

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  • @Learn2Stats
    @Learn2Stats  3 роки тому +9

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  • @upsidedownman256
    @upsidedownman256 Рік тому +27

    Very clear and helpful. I like the no-nonsense presentation.

  • @demitreitler9966
    @demitreitler9966 2 роки тому +31

    I tried working this out on my own for about an hour before I found you. I understand how to do the work and I got it correct so thank you!!!!!!!

  • @airinvisible
    @airinvisible 8 місяців тому +8

    Well done my friend. Crisp and to the point!!

  • @seanjones7474
    @seanjones7474 Рік тому +6

    Awesome vid homie, I failed Stats. once in undergrand and passed it the second time with a "C". Now in grad school, you broke down Standard deviation so simple and perfect. Thanks.

    • @Learn2Stats
      @Learn2Stats  Рік тому

      No problem.
      Let me know if you have questions for other other statistical methods, I can make a video within a few days or give you a quick response if you need it fast.

    • @Learn2Stats
      @Learn2Stats  9 місяців тому

      @levichicwown9760 where am I doing n-1 twice?

  • @melmanuel9483
    @melmanuel9483 Місяць тому +3

    Thank you. I've been looking around and your video is the most helpful one. Straight forward. No nonsense. Thank you.

  • @powervenaris9
    @powervenaris9 2 роки тому +4

    Thank you, I looked at other videos about SAD but those didn't really explain, but you were the one to actually know what you are talking about, thank you very much.

  • @Learnstuffsh
    @Learnstuffsh 9 місяців тому +2

    this was super helpful! thank you so much you saved my life with this video I was so confused in class and this literally helped me finish my homework problem!😊

    • @Learn2Stats
      @Learn2Stats  9 місяців тому

      Glad to help.
      Let me know if there is another question you need help with, I make these videos pretty fast.

  • @stephenray5559
    @stephenray5559 2 місяці тому +1

    Thanks, I literally forgot what exactly summation was. This sorted that all out thanks!

  • @jadeblade14
    @jadeblade14 Рік тому +3

    Omg I'm trying to do college stats homework and this saved my butt. Thank you so much

    • @Learn2Stats
      @Learn2Stats  Рік тому +2

      No problem.
      Please remember the channel for other college stats questions. The videos are based on teaching a class you're probably in.
      I have a series of small videos that cover all the questions of a midterm I handed out.

    • @jadeblade14
      @jadeblade14 Рік тому +1

      @@Learn2Stats wow! Thank you so much! This class is my most difficult one so I'll definitely come back when I need some more help!

    • @Learn2Stats
      @Learn2Stats  Рік тому +1

      I also typically respond within a day.
      I've made videos based on questions in comments within a few days.
      I treat the channel like a tutor session.

  • @orpadoaa
    @orpadoaa 6 місяців тому +2

    Thank youuuu so much, it help me with my reporting. btw I'm from the Philippines. great video ❤

  • @allisonplaysmusic
    @allisonplaysmusic Рік тому +6

    This is SO helpful, thank you 🙌

  • @chrisfritz7947
    @chrisfritz7947 12 днів тому +1

    Will never use this again in my life but thank you

  • @leliacrawford3040
    @leliacrawford3040 2 місяці тому +1

    Thank you for saving my life.

  • @David-sc5kf
    @David-sc5kf 11 місяців тому +80

    this is way too much work. i have 12 sample numbers this is why i hate math.

    • @shhyan2841
      @shhyan2841 11 місяців тому +5

      We have 20🥹

    • @FelixBueno42069
      @FelixBueno42069 11 місяців тому +5

      I have 25 😭

    • @IF_Sports
      @IF_Sports 11 місяців тому +8

      Had about 26 on my stats final today shit was dumb

    • @David-sc5kf
      @David-sc5kf 11 місяців тому +2

      @@IF_Sports there's a way to put it in the calculator but it stil sucks. I just passed stats with a c I'm happy I did not fail lol. Got one more math to go which is business calculus.

    • @IF_Sports
      @IF_Sports 11 місяців тому +1

      @@David-sc5kf stats wasn’t that bad just always studied last second finished with an 82 calc pretty easy fr just gotta pay attention

  • @lo-lifts
    @lo-lifts 2 дні тому +1

    thank you very helpful!

  • @frezahmuchimba5561
    @frezahmuchimba5561 2 роки тому +5

    You're a great teacher

    • @Learn2Stats
      @Learn2Stats  2 роки тому +1

      Thank you!
      Let me know if you have a request, I do video requests for methods, concepts and functions.

  • @aisyahnazula
    @aisyahnazula 6 місяців тому +1

    Your video help me so much
    Thanks

  • @zainch8762
    @zainch8762 2 місяці тому +2

    Thanku so much kab

  • @CarolinaMontelongo-w8g
    @CarolinaMontelongo-w8g 5 днів тому +1

    Thank you!!

  • @megsbookshelf
    @megsbookshelf 2 роки тому +5

    what if my mean comes out to 15.97, and for example my sample numbers are 16.5, 15.6, etc.. do i do 16.5-15.87 or 16.5-15.9 so the decimals are even?

    • @Learn2Stats
      @Learn2Stats  2 роки тому +1

      Great question! If this is for a class, I would ask the teacher as that is the one grading but the best option is to keep the mean at 15.97 and use it for the other calculations. If you don't, you are adding variance to the calculation that isn't there. More often than not, the mean is 15.9767392 or something like that, rounding to the hundredths like you did is fine unless advised differently.
      (16.5- 15.97) and (15.6-15.97) would be how you would apply it with the two numbers you gave. Both of those differences would be squared in that step.
      Let me know if you have any other questions.

    • @megsbookshelf
      @megsbookshelf 2 роки тому +2

      @@Learn2Stats Thanks, do you have any videos on constructing 90% intervals ?

    • @Learn2Stats
      @Learn2Stats  2 роки тому +1

      Now that you mention it, I don't have one that directly talks about that. Most of my test videos have it in there but not one that is just on confidence intervals calculation.
      Here is a short video on understanding the difference between standard error and margin of error. Margin of error is what you use to construct the confidence interval, which I give the equation for.
      ua-cam.com/video/VGCUpzoz6IM/v-deo.html
      Here is another video on understanding the concept of a confidence interval in relation to statistical significance.
      ua-cam.com/video/bOr7oewAcsg/v-deo.html
      Let me know if you have any more questions.

  • @kateoriordan7490
    @kateoriordan7490 9 місяців тому +1

    Is the final result in P value or Z score or say these were distances, would it be plus or minus 4.397cm?

    • @Learn2Stats
      @Learn2Stats  9 місяців тому

      Good question, to do a confidence interval you would want to multiply the standard deviation (4.397) by the multiplier (1.96 for 95% CI) and then add and subtract from the mean.

  • @PapinDiakité
    @PapinDiakité Місяць тому +2

    Fantastic thanks you

  • @Iwillgetrriiich
    @Iwillgetrriiich 7 місяців тому +1

    hii i want to ask if there are repeating elements do you still have to include both in the process for example
    88, 90, 93, 88 were the given does that mean
    (88 - x̄)^2 + .... + (88 - x̄)^2 or just one?

    • @Learn2Stats
      @Learn2Stats  7 місяців тому

      Yes, you would have to do every instance of the number.

  • @thomaswhite3919
    @thomaswhite3919 10 місяців тому +1

    Hi there, if I calculate the standard deviation on my calculator (using the 1-variable table found in the statistics, putting the four sample numbers into the table) I get the same mean, however the standard deviation comes out to be 3.808... I understand your method and can follow it, but am unsure as to why the calculator comes out with a different value. I do not believe I am inputting the data wrong. Do you know what I might be doing wrong to cause this issue?

    • @Learn2Stats
      @Learn2Stats  10 місяців тому

      No problem.
      You are taking the square root of 58/4 when it should be the square root of 58/3.
      Sample standard deviations are n-1 for the denominator.

  • @calebferree2186
    @calebferree2186 2 роки тому +5

    What do I do when I have 45 sample numbers and not just 5

    • @Learn2Stats
      @Learn2Stats  2 роки тому +1

      I used 5 to show the method in a simple way as many people get thrown off by having too many numbers. Follow the steps for the 45. If you have software like Microsoft Excel, I would list them there and do the adding and subtracting there. Use whatever is more convenient for you to find the average.

  • @akhikhanam3463
    @akhikhanam3463 Рік тому +1

    Thank you

  • @ddan1089
    @ddan1089 Рік тому +1

    Respect ❤

  • @Kr_127
    @Kr_127 Рік тому +1

    Thanks

  • @masonbrunworth362
    @masonbrunworth362 2 роки тому +2

    Thanks!

  • @persimmion
    @persimmion Рік тому +2

    what if we don't have sample numbers but just a mean?

    • @Learn2Stats
      @Learn2Stats  Рік тому

      You can't calculate it without the sample size.

  • @persimmion
    @persimmion Рік тому +2

    what if we are already given a mean?

    • @Learn2Stats
      @Learn2Stats  Рік тому

      Go ahead and use it to solve. Usually that is given to save you a step.

  • @kelpR
    @kelpR Рік тому +1

    thxxxxx bro!!!

  • @MsShyNinja08
    @MsShyNinja08 6 місяців тому +1

    What if the exact answer is 21.4537 and my answer is 21.5437 is it ok?

    • @Learn2Stats
      @Learn2Stats  6 місяців тому +1

      That will depend on the teacher.

  • @aikaruaya8183
    @aikaruaya8183 2 роки тому +2

    Thankyouuuu

  • @elviskiplangat6336
    @elviskiplangat6336 2 роки тому +4

    🔥🔥🔥

  • @gl3110
    @gl3110 Місяць тому +1

    I don't fully understand why when you square a negative it becomes positive.. When doing my practice problems it throws me for a loop.

    • @joselyn9912
      @joselyn9912 Місяць тому

      when you square a negative, it’s like multiplying a negative by a negative which in any other situation will give you a positive! :)

  • @souls4187
    @souls4187 Рік тому

    after 58/3, how did you get 4.397??

  • @lukedowneslukedownes5900
    @lukedowneslukedownes5900 2 роки тому +1

    Ty

  • @bethgreenhalgh9738
    @bethgreenhalgh9738 21 день тому +1

    this may be a dumb question and im 3 years late, but why are you deviding it by 4

    • @Learn2Stats
      @Learn2Stats  20 днів тому

      No problem.
      We are dividing by 4 as that is how many observations there are.

  • @EllaMaree-u1o
    @EllaMaree-u1o 8 місяців тому +1

    what if you have two sets of data?

    • @Learn2Stats
      @Learn2Stats  8 місяців тому

      Combine them to make 1 dataset then calculate based on that dataset.
      Another option is to calculate for each data set.
      It depends on what you are being asked to do or what you are analyzing.

  • @hosamessa9069
    @hosamessa9069 2 роки тому +1

    number of observation are 5 so 5-1 =4 ,why did u divide it by 3?

  • @zumibee3901
    @zumibee3901 2 роки тому +11

    how did it became 4.397 did you divide 58/3?????? I'm so confused

    • @Learn2Stats
      @Learn2Stats  2 роки тому +2

      I did the formula by parts and after calculating them put the numbers in their place. 4.397 is the square root of 58/3.

    • @salayaallaysajoyrubido9255
      @salayaallaysajoyrubido9255 Рік тому +1

      ​@@Learn2StatsThankyou I learn a lot today 😊❤

    • @brandyparker5809
      @brandyparker5809 Рік тому +1

      @@Learn2Stats Hey, sorry to bother you. Kindly, what do you mean by the number in place? I'm confused; how did he get 4.397? I divided 58/3 it gives me a totally different number.

    • @Learn2Stats
      @Learn2Stats  Рік тому

      @@brandyparker5809 1 more step to do. Square root 58/3 and you should get the answer.

  • @gabrielleamundson64
    @gabrielleamundson64 2 роки тому +2

    Thank you so much

  • @pr1n05
    @pr1n05 9 місяців тому

    My homework says i need excel!!! I did this for every single problem , however its 6 numbers. AND IT KEEPS SAYING ITS WRONG. I dont want to pay for excel! Please help?!!

    • @Learn2Stats
      @Learn2Stats  9 місяців тому

      What are the 6 numbers and what do you get?

  • @farishaampatuan9054
    @farishaampatuan9054 Рік тому

    Why the (2) and (5) doesn't have - compared to (-5) and (-2)

    • @Learn2Stats
      @Learn2Stats  Рік тому

      The 2 is from (9-7) and the 5 is from (12-7). The x values are greater than the mean so they will be positive.

  • @voidyt6520
    @voidyt6520 Рік тому

    I thought you divide by the number of data points?

    • @Learn2Stats
      @Learn2Stats  Рік тому

      For the sample, you divide by the number of data points minus 1.
      For the population, you divide by the number of data points.

  • @wevibinwidsye
    @wevibinwidsye Рік тому

    anyone understand how he got 4.397 cause when I did 58 divided by 3 it gave me 19.333

  • @westonsummers8728
    @westonsummers8728 Рік тому +2

    💀