I have a data set on gross income and I'm trying to display the percent of total gross income (in a pie chart) that comes from 1. wage income 2. interest/dividend income and then 3. other income (Business and farm income, ss income, etc.).

How do I create a new variable that is the sum of all of the 'other' variables. Basically, I want a pie Chart that Shows percent of total gross income that Comes from
1. wages
2. interest and dividend
3. other

Thanks!