39. The following MATLAB commands create a sine-shaped signal y(t) that contains random noise: t = 0:.05:10; y = sin(t)-0.1+0.2*rand (1, length(t)); Write a MATLAB program that uses these commands to create a noisy sine-shaped signal. Then the program smooths the signal by using the three- points moving-average method. In this method the value of every point i, except the first and last, is replaced by the average of the value of three adja- cent points (i-1, i, and i+1). Make a plot that display the noisy and smoothed signals