Average invoice amount

[BORUCH]

i have a table that has the following info how can i get a formula that will tell me the average invoice amount for a particular customer I would like a dax formula not an excel

CUSTOMER NUMBER	CUSTOMER NAME	INVOICE NUMBER	INVOICE AMOUNT
A001	JACK	123	$1,000
A001	JACK	456	$6,521
B001	BOB	789	$500
B001	BOB	101112	7698

 

[JEC]

=CALCULATE(AVERAGE(Table1[INVOICE AMOUNT]),ALLEXCEPT(Table1,Table1[CUSTOMER NAME]))

 

[JEC]

Or use the customer number, it is safer

=CALCULATE(AVERAGE(Table1[INVOICE AMOUNT]),ALLEXCEPT(Table1,Table1[CUSTOMER NUMBER]))

 

[BORUCH]

=CALCULATE(AVERAGE(Table1[INVOICE AMOUNT]),ALLEXCEPT(Table1,Table1[CUSTOMER NAME]))

does this take into account the invoice number at all ?

 

[BORUCH]

basically what i want is a average of invoice # 123 and 456 for customer number A001

 

[BORUCH]

what i need it to do is to first total up each individual invoice then make an average since each invoice can have multiple line items