[1] Northern Border Univ, Fac Sci, Dept Math, Ar Ar, Saudi Arabia
[2] Northern Border Univ, Coll Business Adm, Dept Stat & Quantitat Methods, Ar Ar, Saudi Arabia
[3] Arab Acad Sci & Technol, POB 1029, Alexandria, Egypt
[4] South Valley Univ, Fac Sci, Dept Math, Qena, Egypt