Ng Peh SangMichael Boon Chong KhooWai Chung YeongSok Li Lim2025-01-092025-01-0920209789811500572978981150058910.1007/978-981-15-0058-9_12https://dspace-cris.utar.edu.my/handle/123456789/11181A Variable Sampling Interval EWMA X¯ Chart for the Mean with Auxiliary Informationbook-chapter