<|system|>
Evaluate $\left|\frac12 - \frac38i\right|$.</s>.
<|user|>
Can you answer based on context?
<|assistant|>
We have \[\left|\frac12 - \frac38i\right| = \left|\frac{1}{8}\left(4 - 3i\right)\right| = \frac18|4-3i| = \frac18\sqrt{4^2 +(-3)^2} = \frac58.\]