Here is the magnitude response of the 40th-order lowpass FIR filter with a passband frequency of 400 Hz and a stopband frequency of 500 Hz, designed using the Hamming window.

Would you like further details on this response or have any questions?

Here are five related questions for further exploration:

1. How does the choice of window function affect the filter's performance?
2. What happens if you increase the filter order to 60 or higher?
3. How do you design a highpass FIR filter using similar parameters?
4. What is the significance of the transition width in FIR filters?
5. How does the sampling rate affect the design and response of the filter?

Tip: Increasing the filter order improves the sharpness of the transition but also increases computational complexity.