Measurement activities were designed in this study on the basis of authentic professional practices in which linear regression is used, to study considerations of variability by students in Grade 12 (aged 17-18). The question addressed in this article is: In what ways do secondary students consider variability within these measurement activities? Analysis of students' reasoning during these activities in one classroom (N = 13) suggests that students considered variability in four ways: noticing and acknowledging variability, measuring variability, explaining variability, and using investigative strategies to handle variability. We conclude that the measurement tasks based on authentic professional practices helped students to reason with relevant aspects of variability. Finally, we discuss curricular and research implications.