Finding Percentage of Total with Magic ETL

I want to create a % of total pageviews column (e.g. the row for California would be 40% for pageviews in the dummy data set I've included).

I then want to divide % of total pageviews by % of population for each state in a filled map.  I've read Dojo articles about doing all this with magic ETL but they are hard to follow.


Could someone provide clear step by step directions?