1. Department of Statistics and Mathematical Sciences, Faculty of Pure and Applied Sciences, Kwara State University, Malete 1530, Nigeria
2. Department of Statistics, Faculty of Physical Sciences, University of Ilorin, Ilorin 1515, Nigeria
3. Department of Mathematics, Faculty of Science, Taibah University, Al-Madinah Al-Munawara 42353, Saudi Arabia
4. School of Mathematical Sciences, Universiti Sains Malaysia, Pulau Pinang 11800, Malaysia