4. Table Prob. 4 gives 50 sample values of a random signal. (a) Estimate the mean and standard deviation of the signal. (b) Using an interval Ay=0.5 V, draw the Pj and Cj discrete probability distributions for the signal. -0.59 -1.00 0.65 2.15 0.42 1.02 -0.25 1.36 0.03 0.11 0.99 0.91 0.89 0.05 0.26 -0.63 -0.06 -0.61 -0.34 0.04 0.17 1.43 0.33 0.77 0.95 -0.13 0.39 -1.69 -0.42 1.90 1.24 -0.30 -1.23 -0.08 2.47 -0.07 -0.71 2.61 -0.25 0.79 0.21 -0.89 0.03 -1.00 -0.33 0.99 -1.97 -2.26 -0.32 -0.66