3. A stationary random sequence x[n] with mean mx = 4 and autocovariance Cx[n] = { 4-n, n≤3 otherwise 0, is applied as an input to an LTI system whose impulse response h[n] is - h[n] = u[n] — u[n — 4], where u[n] is a unit step sequence. The output of this system is another random sequence y[n]. Determine: mean sequence my [n] (b) cross-covariance Cry [m, n] between x[m] and y[n], and (c) autocovariance cy[m, n] of the output y[n]