Proficient-level: "Year-to-date, Oracle had earned a 1.34 percent return. During the same time period, Valero Energy earned 7.96 percent and McDonald's earned 0.88 percent. If you have a portfolio made up of 30 percent Oracle, 25 percent Valero Energy, and 45 percent McDonald's, what is your portfolio return?" (Cornett, Adair, & Nofsinger, 2016, p. 235).