different criteria with same headings

hi friends!

I have a db with those headings: |nummachine | weeknum | cost
I wanna calculate daverage per machine... how can I write the criteria table so I use the same headings every daverage?

suppose it's the criteria table:

Attachment 505445

now I wanna do it to the second row ...etc (with the same headings)
put attention please, I don't meant to OR statement
I meant calculate daverage for every row

thanks u
Ben