standard error of the difference of the sample means is: rt( (sigma1^2/n1) + (sigma2^2/n2) ) Z = (xgem1 - xgem2) - (u1 -u2)/ rt((sigma1^2/n1)+(sigma2^2/n2)) confidence interval = xgem1 - xgem2 +/- Z(1-alfa/2)*standard error (zie hierboven)

I'm going to encourage you a little, to help you get started. :)

I am going to encourage you a little, to help you get started :)
Since you looked us up and read the site enthousiastically, I would like to offer you a big discount.