1. Build histograms of sampling distributions g 1l l 1 and g 2l l 2 . The tails of the histograms where probabilities become very small are approximated by zero. 2. Build a histogram of sampling distribution q(r) ofr r~l l 1 .l l 2 by considering each bin [r 1 , r 2 ] and by adding all the joint probabilities of different values of concentrations which give a ratio rM[r 1 , r 2 ]. 3. Compute the mean and the 95% confidence interval from the ratio histogram.