How do I generate weighted centroids for ZCTAs using population from census tracts

Discussion created by lingcx on Dec 9, 2013
Latest reply on Dec 10, 2013 by lingcx
In ArcGIS 10.1, how do I calculate the weighted centroid of ZCTAs, where I want the weight to be a population from census tracts?

Here is the thing:
1) ZCTAs go out of the boundary of the counties that I'm interested in performing this weighted centroild? Should I clip the ZCTA using the county boundary?
2) The boundaries of ZCTAs and tracts do not nest within each other. And for urban areas, census tracts are smaller, but for rural areas, ZCTAs are smaller.
3) I was recommended using a raster. So I joint the number of population of interest with the shapefile for each census tract, and then calculated the density by dividing the pop by area, and then convert it into a raster layer (after which I got stuck).
And I tried to follow the instructions given by and But I'm not sure how specifically should I do (currently don't have spatial analyst tool license). Can I still do it without this license? Or I need to purchase it?