Answer:Here's how to calculate the percentage change: 1. Find the difference: 72 units - 60 units = 12 units 2. Find the ratio of the difference to the second quantity: 12 units / 60 units = 0.2 3. Convert the ratio to a percentage: 0.2 * 100% = 20% Therefore, the percentage change of the first quantity (72 units) with reference to the second quantity (60 units) is a 20% increase.