Optimum stratification

Summary This paper considers the problem of optimum stratification on a concomitant variablex when the form of the regression of the estimation variabley on the concomitant variablex as also the form of the variance functionV(y|x) are known. Minimal equations giving optimum strata boundaries have been obtained for Neyman and proportional allocations. Since the minimal equations cannot be solved easily, various methods of finding approximate solutions have been given. A comparison of approximate solutions with the exact solutions is made for certain density functions.