1. Department of Mathematics and Statistics, University of Energy and Natural Resources, Sunyani, Ghana
2. Department of Statistics and Actuarial Science, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
3. Department of Statistics and Actuarial Science, University of Ghana, Accra, Ghana
4. Department of Mathematics and Statistics, Ghana Communication Technology University, Accra, Ghana
5. Department of Mathematics, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana