1. Department of Statistics and Operations Researches, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
2. Mathematics Department, College of Science and Humanities Studies, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
3. Department of Engineering Mathematics and Physics, Faculty of Engineering, Mansoura University, Mansoura 35516, Egypt
4. Basic Science Department, Faculty of Computers and Informatics, Ismailia 41522, Suez Canal University, Egypt