1. School of Statistics, Shanxi University of Finance and Economic, Taiyuan, China
2. Department of Statistics, University of Malakand, Dir (L), KP, Pakistan
3. Department of Statistics, Yazd University, P.O. Box 89175-741, Yazd, Iran
4. Department of Statistics, Abdul Wali University Mardan, KP, Pakistan
5. Department of Statistics, Islamia College Peshawar, KP, Pakistan