As in Chapter 2, we will consider a population (lot) of size N, containing D NC items. However, instead of taking a single sample, we will take k, say, random samples of sizes n = (n ₁,..., n_k ), respectively, without replacement. Let Y  (Y ₁,..., Y_k ) be the numbers of truly NC items in the corresponding samples, with y = (y ₁,..., y_k ) as a realized value of Y.