Given $(9 \text{ inches})^{1/2}=(0.25 \text{ yards})^{1/2}$, which one of the following statements is TRUE?

1. $3$ inches $= 0.5$ yards
2. $9$ inches $= 1.5$ yards
3. $9$ inches $= 0.25$ yards
4. $81$ inches $= 0.0625$ yards