* *
Novi Putriasari
^{(1)}, Sigit Nugroho
^{(2)}, Ramya Rachmawati
^{(3)}, Winalia Agwil
^{(4)}, Yosep O Sitohang
^{(5)}
(1)
Mathematics Department, The University of Bengkulu
,

(2)
Mathematics Department, The University of Bengkulu
,

(3)
Mathematics Department, The University of Bengkulu
,

(4)
Mathematics Department, The University of Bengkulu
,

(5)
Statistics Indonesia, Branch Office of Bengkulu Province