English language learners are a growing demographic in secondary, two-year, four-year and research institutions where many students encounter their first course in statistics. In the statistics education literature, recent calls have been made to improve statistical education for underserved student populations, including English Language Learners (ELLs). Some have investigated how ELLs interpret instructional material and classroom practices in the statistics classroom. This study uses a sequential mixed methods approach to investigate how Spanish-speaking ELLs may respond differently to assessment items about measures of center and variation. Comprehensive analyses of this type are essential in order to identify bias and ensure fair comparisons across participant populations. Findings indicate that ELLs do not comprehend context or understand some statistical terms in the same way as non-ELLs. Study limitations, implications, and recommendations are discussed.