Filtering $(10$ Points$)$ a$.$ Perform $3-$point moving average $\{$y$[$n$]=![$#$$\%]$ $ $![$#$]$ $ $![$#$(\%])\}$ on x$[$n$]=[4,5,1,3,0,4,2].(4$ points$)$ b$.$ Draw, in the frequency domain, examples of spectra before and after: i$.$ high$-$pass filtering, ii$.$ low$-$pass filtering, and iii. Band$-$pass filtering. Draw any pre$-$ and postfiltering spectrum you like, but please define the frequency of peaks and filter cutoff values. $(6$ points$)$