Carol M. Kopp edits features on a wide range of subjects for Investopedia, including investing, personal finance, retirement planning, taxes, business management, and career development.

In his book The Mathematical Universe, mathematician William Dunham wrote of John Venn’s namesake legacy, the Venn diagram, “No one in the long history of mathematics ever became better known ...

Easy-to-understand visualizations for Ranked-Choice Voting elections: sankey, bargraphs, and tables. Interactive and print-friendly options available. Supports most common tabulators.

The company has several marketplace and auction partners as well. Although eBay has hosted listings for used car sales and auctions on the site for years, it currently leaves it to the dealer to ...