Averaging using Group by and Distinct in sql - group-by

Question

This is a bit convoluted but I will try to make it not so. Below is a snippet of the data and the intended result below it. For every combination of state, area, indcode, and ownership I want to calculate an average. My knowledge of AVG in SQL would average the entire column not just specific values.
state areatype area period indcode ownership sites employment
32 05 000001 01 102800 12 25 256
32 05 000001 01 102900 13 6 26
32 05 000003 01 102800 12 774 1874
.
.
32 05 000001 02 102800 12 27 239
32 05 000001 03 102800 12 28 241
32 05 000001 04 102800 12 29 248
Intended result
32 05 000001 00 102800 12 27 246
Would the following code do this or be even close?
Select avg(employment, sites)
From Select (Distinct(state, area, indcode, ownership) from dbo.tablename;

Answer 1

select
[state], areatype, area, '00' [period], indcode, ownership,
avg(sites) sites, avg(employment) employment
from dbo.tablename
group by [state], areatype, area, indcode, ownership;
Got this mostly by trial and error and help from another site. Not really sure why it works but its close enough.