1. Department of Mathematical Science, Faculty of Applied Science, Umm Al-Qura University, Mecca, Saudi Arabia
2. Directorate of Economics and Statistics, Planning Department, New Delhi, India
3. Department of Mathematics (Statistics Option) Programme, Pan African University, Institute for Basic Science, Technology and Innovation (PAUSTI), Nairobi, 6200-00200, Kenya
4. Department of Mathematics, Faculty of Science, Mansoura University, Mansoura 35516, Egypt