So, first of all I have a random signal, then I find out that it is nothing but sum of regular waves. Then if I can find it out, I can find out what omega and what a are associated. Then, I plot that graph; it turns out that the graph represents, , you know, Rayleigh distribution. So, I make an assumption, look I will consider this graph to be Rayleigh distribution. Now, I have to find out what is my average wave height or significant wave height. All I will do, take the area under the graph, use this formula. People do not believe it. You take this signal that from where you started in the first place, take all the heights there, find out those like what we did before, see the average, you will see that they will match, if the signal was Rayleigh distribution.