Consider an audio-band signal with a nominal bandwidth of 4 kHz that has been sampled at a rate of 8kHz. Suppose that we wish to isolate the frequency components below 80 Hz with a filter that as a passband 0 < F < 75 and a transition band 75 < F < 80. (a) Find an appropriate decimation factor to be applied. (b) Given that the filter to be used has a passband ripple of d = 10-2 and a stopband ripple of d10-4. Find the length of the linear phase FIR filter that can satisfy these requirements. (Hint: Use the Kaiser Formula). (e) Suppose we want to implement the solution using a two stage decimation process where D = 25. Find D and the total length of the two FIR filters that are required.