DEVELOPMENT STUDY OF GLMM-GEE-TREE REGRESSION MODELLING FOR BETA DISTRIBUTION RESPONSE DATA (IMPLICATIONS OF GINI RATIO MODELING IN INDONESIA, 2018-2024) - Sihombing, Pardomuan Robinson; Erfiani, Erfiani; Notodiputro, Khairil Anwar; Kurnia, Anang (BAREKENG: Jurnal Ilmu Matematika dan Terapan, 2026)