So right now I have 3 groups of 5 x values(15 x values in total. How do I perform a loop where I use the values after I get the mean?? so how would i create a matrix such that . M= [x1-Mean_allx ; x2-Mean_allx ; x3-Mean_allx ;...... ; x15-Mean_allx] ?? Could it also be possible for the value to be Matrix to be averaged?