Hi,
If your question is along the lines of adding the mean and standard deviation as annotation over the scatter plot, try the following code snippet:
x = linspace(0,3*pi,200);
y = cos(x) + rand(1,200);
scatter(x,y)
meanVal = mean(y);
stdVal = std(y);
dim = [.2 .5 .3 .3];
str = sprintf('Mean: %f\n Std: %f',meanVal,stdVal);
annotation('textbox',dim,'String',str,'FitBoxToText','on');
Abel