8.2 PSD estimation. The data files m7_5x.dat and m7_5y.dat in the companion software PARSE contain two data records that are discrete-time (with 1000 Hz sampling rate) sample functions of two zero-mean ergodic random processes X(t) and Y (t), respectively. With the help of PARSE, calculate and plot the power spectra (with segment length: 64, over- lapped N: 0, max frequency: 500, window type: 0, spectrum type: 1, RP type: 1) of X(t) and Y (t), respectively. Is X(t) white? Is Y(t) white?