Vaughn sells books, movies, and magazines to a wide customer base. In a typical month, about $40\%$ of its sales volume is from books, $40\%$ from movies, and $20\%$ from magazines. The selling price and cost information for each of these product categories is as follows.

$\backslash$table$[[,$Books,,Movies,,Magazines$],[$Selling price,$$10,,$$$14,,$$$5$