21.5 Exercise 6

When an unknown resistance $R_{\text{x}}$ is placed in a Wheatstone bridge, it is possible to balance the bridge by adjusting $R_{3}$ to be $\text{2500} \Omega$. What is $R_{\text{x}}$ if $\frac{R_{2}}{R_{1}} = 0 . \text{625}$?