Casey has a recipe for beef stew. This table shows the pounds of beef needed to make different numbers of servings of the beef stew. A table is shown with two rows. The first row is labeled Pounds of Beef followed by two, three, four, and six. The second row is labeled Number of Servings followed by seven, a question mark, fourteen, and twenty-one. What number of servings can Casey make with 3 pounds of beef?