Super learner

03 Dec 2022

Posted on:

24 Nov 2022

1

Vague answer about why average was applied in both SQL and Tableau

Hello,

This is not a question, but rather more like a suggestion. The reason mentioned in the video about applying average function in SQL and Tableau was a bit mistaken and quite vague in nature. For example, we have the average salaries of employees in the Marketing department for the year 2000, similarly, we have some other numbers for other departments too. Mathematically, it does not make sense to just sum up a few averages, rather we can take a few averages and find the average to those to get the average for the whole picture. For instance, the average of the numbers from 1 to 5 is 3, and the average of the numbers from 6 to 10 is 8, if we sum 3+8 = 11, this is not meaningful, but an average of 3 and 8 gives 5.5 which is the average of the numbers from 1 to 10.

I hope the explanation I provided is clear and I hope the team can clarify this matter to the audience in some way. Thank you!

Instructor
Posted on:

03 Dec 2022

1

Hi Md Abdur Rakib!

Thanks for reaching out.

Indeed. If I understand correctly what you mean, isn't it that at minute 1:40 of the following video https://learn.365datascience.com/courses/sql-tableau/chart-3-visualizing-the-solution-in-tableau/ we do exactly that - we chose to obtain the average of the selected values.
If you are referring to the fact that SUM() has been used beforehand, then please consider that this is the operation applied by Tableau by default. What is important is to change it for the final output.

Hope this helps but please feel free to get back to us should you need further assistance.
Kind regards,
Martin