The ratio, product, chain ratio, chain product, chain regression and ratio-cum product estimators have been considered by Chand (1975), Kiregyera (1980, 1984), Upadhyaya et. al. (1990, 1992), Srivastava et. al. (1990), Prasad et. al. (1992), Sahoo and Sahoo (1993), Singh (1993). Most of them...