1. Department of Statistics and Operation Research, College of Science, Qassim University, Buraydah 51482, Saudi Arabia
2. Department of Mathematics, Faculty of Science, Mansoura University, Mansoura 35516, Egypt
3. Department of Mathematics, International Telematic University Uninettuno, I-00186 Rome, Italy
4. Mathematics Department, Faculty of Science, Sohag University, Sohag 82524, Egypt
5. Faculty of Business Administration, Taibah University, Saudi Arabia