Barfour Kwame Asare Usmanu Danfodiyo University   Dept of Mathematics Usmanu Danfodiyo University P.M.B. 2346 Sokoto, Sokoto Nigeria   nanabkasare@yahoo.com   http://www.udus.edu.ng           JEL Areas: C5 : Econometric Modeling: General C3 : Multiple or Simultaneous Equation Models: General