1 Reply Latest reply on Dec 13, 2016 5:02 AM by Mahfooj Khan

    Mismatch in Skew Value in Excel & Tableau Summary Card

    Sumeet Bedekar

      Hi Tableau Lovers,

       

      A measure of the tendency of your data to have extreme values to one side. Positive skewness means the extreme values are to the right, while negative skewness means the extreme values are to the left.

       

      I have sample data set as shown below  and wanted to compute on this sample data set.

       

        Skew.PNG

       

      Formula:-

      - skew 3 formula.png

       

      First Result in Excel :-  Skew = - 0.64052

      Skew 2 Excel.PNG

      Second Result in Tableau:-  Skew = - 0.641

      skew 4 in tableau.PNG

       

      Third Result in Tableau Summary Card :-  Skew = -0.54

      skew summary card.png

      Thus,

      Skew Summary 1.PNG

       

      From above snap shot, we came to know that Skew in Tableau Summary card is showing different value.

       

      Please shed light on this.

       

      Mahfooj Khan Kindly have a look into this

       

      Regards,

      Sumeet

        • 1. Re: Mismatch in Skew Value in Excel & Tableau Summary Card
          Mahfooj Khan

          There are two function it takes - SKEW() and SKEW.P() and the difference is that incase of SKEW only, it considers the distribution of the data as a sample and incase of SKEW.P, it considers the data as the entire population. Mathematically, in place of n if you take n-1, the formula will take the data as a population distribution. So your -0.64 comes when you apply sample skew function, and -0.54 is observed when you calculate skewness of a population.

           

          SKEW() on a sample

          SKEW.P() on a population

           

          Hope this help.

           

          Mahfooj

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