Which numeric variable's missing values are not missing at random, as evidenced by a significant difference…

Which numeric variable's missing values are not missing at random, as evidenced by a significant difference…: a task in SmolDataEnvs-harbor-train-sandbox: 📊 SmolDataEnvs: Harbor (train) (Harbor dataset). Files (in /home/user/input, no subfolders): - train.csv - test.csv