Chapter 5 - Cost-Volume-Profit Relationships - The Foundational 15 - Required - Page 217: 13

The estimated percent increase in net operating income of a 5% increase in sales = 5 $\times$ 4 = 20 %

This degree of operating leverage shows that the Oslo Company’s net operating income grows four times as fast as its sales. Therefore, the estimated percent increase in net operating income as a result of a 5% increase in sales = 5 $\times$ 4 = 20 %