To determine which option is a proportion, we need to check if the two fractions are equivalent. A proportion states that two ratios are equal.
Option 1: \( \frac{5}{6} = \frac{15}{18} \)
To check if these fractions are equal, we can simplify \( \frac{15}{18} \):
- The greatest common divisor of 15 and 18 is 3.
- \( \frac{15 \div 3}{18 \div 3} = \frac{5}{6} \)
Thus, \( \frac{5}{6} = \frac{15}{18} \) is true.
Option 2: \( \frac{5}{6} = \frac{20}{18} \)
To check if these fractions are equal, we can simplify \( \frac{20}{18} \):
- The greatest common divisor of 20 and 18 is 2.
- \( \frac{20 \div 2}{18 \div 2} = \frac{10}{9} \)
Thus, \( \frac{5}{6} \neq \frac{20}{18} \).
Conclusion: Option 1 is a proportion because \( \frac{5}{6} = \frac{15}{18} \). Option 2 is not a proportion because \( \frac{5}{6} \) does not equal \( \frac{20}{18} \).
Therefore, the answer is Option 1.