Decomposition Tree - Calculation Issue

[Anonymous]

Hi All, 

So I am using a Measure to analyze in Decomposition Tree.

The measure takes an average of employee's contribution.  

The summarized average is not adding up to the bi-furcated average. Is this normal? Or am I missing something here?

Please see the attached example for your reference.

In the attached photo - you will see that - Total Average is called out as 9.69

 

however when I bi-furcate it into the area:

Productive: 7.98

Break: 1.60

Other: 0.40

The sum of these three comes close to 9.98 which is greater than our total average.

Please help me understand this issue.

Regards

Raj

[Anonymous · Accepted solution]

It is simple math , you can not add average values and expect the total sum of those averages to be equal to total average.

[amitchandak]

@Anonymous , what us your average formula

Is it like Averagex(Table, divide(Table[Val1],Table[Val2]))

if so it should be

Divide(sum(Table[Val1]),Sum(Table[Val2]))

[Anonymous · Accepted solution]

It is simple math , you can not add average values and expect the total sum of those averages to be equal to total average.

[Anonymous · Accepted solution]

@rajprabhakaran2
Let's have 19 numbers in groups 6.10 and 3:
the averages are:
30/6-5
40/10-4
30/3-10

now add these averages 5 + 4 + 10 - 19
as a whole (30+40+30)/19-5.26

5.26 will never be equal to 19. Similarly, you are getting difference in average. It can only be true if all n values are the same:

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