You are building a symbol map that will display the location and the relative size of each public school in a country. Your data source includes fields for Name. Latitude, Longitude, and Number of Students. You open a new worksheet. What should you do first to build the map? Drag Number of Students to Size on the Marks card. Drag Latitude to the Rows shelf and Longitude to the Columns shelf. Drag Name to Detail on the Marks card. Configure the X and Y axis on a background image.