1. Department of Business Administration, Faculty of Administrative Sciences, University of Brawijaya, Veteran St., Ketawanggede, Kec. Lowokwaru, Malang City, East Java 65145, INDONESIA
2. Department of Statistics, Faculty of Mathematics and Natural Sciences, University of Brawijaya, Veteran St., Ketawanggede, Kec. Lowokwaru, Malang City, East Java 65145, INDONESIA