It looks like you've uploaded a problem set for an electrical engineering course (ECE 4624) that covers a range of topics, including system analysis in the time and frequency domains, plotting signals, and working with Z-transforms. Would you like help with a specific problem from the set? Let me know which question you’d like assistance with!

Here are some example questions that expand on the topics in your problem set:

1. How do you determine if a discrete-time system is causal and stable?
2. What are the steps to compute the Z-transform and inverse Z-transform for a given sequence?
3. How can you efficiently implement a difference equation in Python for signal processing?
4. What is the relationship between a system's impulse response and its frequency response?
5. How does convolution in the time domain relate to multiplication in the Z-domain?

Tip: When analyzing systems, always start by checking linearity and time-invariance, as they significantly impact other system properties like causality and stability.