Cross-multiply to see if the ratio forms a proportion Select Yes it forms a proportion and No if it does not. (1)/(4)=(5)/(20) Yes

To determine if the given ratio forms a proportion, we need to multiply the fractions and see if they are equal.<br /><br />$\frac{1}{4} = \frac{5}{20}$<br /><br />To multiply the fractions, we can cross-multiply:<br /><br />$1 \times 20 = 4 \times 5$<br /><br />$20 = 20$<br /><br />Since the products are equal, the given ratio forms a proportion.<br /><br />Therefore, the answer is Yes.