1. Department of Mathematical Sciences, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh 11671, Saudi Arabia
2. Department of Statistics, Quaid-i-Azam University, Islamabad 44000, Pakistan
3. Pakistan Institute of Development Economics, Islamabad 44000, Pakistan
4. Department of Mathematics and Statistics University of Saskatchewan, Saskatoon, SK, Canada
5. Department of Statistics, University of Malakand, Dir (L), Chakdara, Khyber Pakhtunkhwa, Pakistan
6. Higher Institute of Engineering and Technology at El-Mahala El-Kobra, Egypt