For my proportional symbols, I did have some issue with the negatives. The symbols were inversed so the negatives closer to zero had larger symbols than the ones further away. My solution was, once the negatives were isolated, I multiplied them by negative one to make them positive and the symbols made logical sense after that. To create a bivariate choropleth map, you'll need two variables. The range of those variables need to be broken down and portioned into classes. Once the two variables have classes assigned, those separate classes need to be combined and symbolized. A merging color scheme will be established to show the relationship between the two variables as they increase or decrease.
The place where maps are.