The calculated value of $Z_{b2}$ is approximately 16.905.

Would you like further details or have any other questions about the calculation?

Here are some related questions:

1. How does each parameter in the equation influence the value of $Z_{b2}$?
2. Can the value of $Z_{b2}$ be simplified further in specific scenarios?
3. What physical interpretation can $Z_{b2}$ have in the context of electrical or impedance-related problems?
4. How would changes in $a$ or $Z_0$ affect the final result?
5. Can this formula be derived or related to other common engineering equations?

Tip: In complex equations like this, breaking them down into smaller parts helps to ensure that each step is calculated correctly and verifies assumptions.