I am fairly new to arcgis, so this is probably a really simple task, but I would like to ask advice so I can learn how to do it. 
Basically,
I have a polygon layer that has attributes for each house within a set of neighborhoods each house has the attribute of which neighborhood that it belongs to as well as its water consumption.
My problem is this, I want to be able to find the average water consumption for each neighborhood by averaging the water consumption of each house within that neighborhood, and then be able to show average water consumption for each neighborhood on a choropleth map.
Could anyone give me advice on what is the best way to go about solving this problem?