Mathematical inquiry is an approach whereby students respond to ill-structured, open-ended questions that reflect the authentic problems we encounter in 'real' life (Allmond, Wells & Makar, 2010). An open-ended ill-structured question has no single correct answer and often contains ambiguities in the problem that require students to make a number of decisions (Makar, 2012). In an inquiry-based lesson, students are required to negotiate the question meaning and context; decide on the mathematical evidence that would be needed to address the question; decide how to collect, organize, and represent the evidence collected; interpret the evidence; and, present and justify the findings in the form of a conclusion with supporting evidence (Fielding-Wells, 2010). In this article, the authors present a framework for guiding mathematical inquiry and use it to explore the age-old question: Are athletes getting better over time? Their research, once again, underscores the benefit of having students explore data representations and interpretation in authentic contexts.