1. The problem is to determine if the proportion $$\frac{4}{28} = \frac{5}{35}$$ is true or false. 2. Simplify each fraction separately. 3. Simplify $$\frac{4}{28}$$ by dividing numerator and denominator by their greatest common divisor (GCD), which is 4: $$\frac{4 \div 4}{28 \div 4} = \frac{1}{7}$$ 4. Simplify $$\frac{5}{35}$$ by dividing numerator and denominator by their GCD, which is 5: $$\frac{5 \div 5}{35 \div 5} = \frac{1}{7}$$ 5. Since both simplified fractions are equal to $$\frac{1}{7}$$, the proportion is true. Final answer: The proportion $$\frac{4}{28} = \frac{5}{35}$$ is **Cierta** (true).