Using vlookup with sum/average

[city]

Hi,

Please help me with this. This is really urgent that i need to learn this. I really don't know how to use vlookup and sum/average function together.

I already tried AVERAGE(VLOOKUP(A2,data!A$2:C$13,3,FALSE)), but it only returns the first value in the data tab.



I was thinking that vlookup data should be placed in an array.. but don't know how... =(

Pivot table is placed there only as reference as to see if calculations will be correct.

Can someone please educate me on this.. I would really appreciate this. Thank you.