Average of two columns from different tables,without access to model

[Anonymous]

Hello world, 
I have a huge issue of calculating an average based on two different columns. 
I thought using this calc,

AVGof 2 cols =
AVERAGEX(
	ADDCOLUMNS(
		SUMMARIZE(
			'<tablename>'
			,'<tablename>'[Table 1]
			,'<tablename>'[Table 2]
		)
		"ND1" , [Number of Days]
	)
	, [ND1]
)

but Table2 is in another tablename (let's name it table name 2). so I cannot use summarize, as it is taking only a single tablename.
I also tried allexcept, but yet it didn't work. 
This is the data along with the result,any help would be appreciated.

Tablename 1	Tablename 2	Tablename 1		Result
Name	Work	Days
VS	Book	0		2
VS	Book	1		2
VS	Book	2		2
VS	Book	3		2
VS	Book	4		2
VS	Show	0		0.5
VS	Show	1		0.5
VS	Swim	0		0.5
VS	Swim	1		0.5
VI	Book	0		4
VI	Book	8		4
VI	Show	0		2.66
VI	Show	1		2.66
VI	Show	7		2.66
VI	Swim	0		0
TV	Book	0		5.33
TV	Book	1		5.33
TV	Book	15		5.33
TV	Show	0		0

[v-alq-msft]

Hi, @Anonymous 

I wonder what 'Tablename 1' and 'Tablename 2' are like and the relationships between tables.

Best Regards

Allan

[Anonymous]

eventually these are 2 dim tables that are connected through a fact table.

[vanessafvg]

how is the data related to each other from the two tables

[Anonymous]

I guess (as I have no direct access to the model itself) that it is a many to many relationship using a bridge table.
Thanks @vanessafvg 

[vanessafvg]

does this old thread help at all?

https://community.powerbi.com/t5/Desktop/Combining-2-tables-and-Summarize/td-p/255606

[Anonymous]

Well, as you can see on my sample calculation I tried to use summarize, but the command accepts columns from 1 table, and my 2 columns are in 2 different tables, so I don't think it helps somehow (or in a way that I can think of, pretty new in PBI)