A proportion is an equation that states that two ratios are equal. To determine which option is a proportion, we can cross-multiply and check if the products are equal.
Option 1: 5/6 = 15/18
Cross-multiply: 5 * 18 = 90 6 * 15 = 90
Since both products are equal (90 = 90), Option 1 is a proportion.
Option 2: 5/6 = 20/18
Cross-multiply: 5 * 18 = 90 6 * 20 = 120
Since the products are not equal (90 ≠ 120), Option 2 is not a proportion.
Therefore, Option 1 is a proportion.