Understanding, analyzing, and conveying information based on data are essential competencies students need in navigating today's data-driven world. Unfortunately, many junior high school students in Indonesia have yet to reach an adequate level of statistical literacy, especially when it comes to reading meaning from data and explaining it to others. Addressing this gap, the present study examines whether combining the Contextual Teaching and Learning (CTL) approach with elements drawn from Lampung Culture can strengthen statistical literacy among seventh-grade students at SMP Negeri 1 Anak Ratu Aji, with a specific focus on the topic of data and diagrams. A quasi-experimental design following the Non-Equivalent Control Group format was employed, involving two groups of 23 students each: class VII.C as the treatment group and class VII.E as the comparison group, both determined through purposive sampling. An essay-type assessment served as the main instrument, having passed checks for validity, reliability, difficulty index, and discriminating power. Statistical procedures applied included the Liliefors test for normality, Fisher's test for homogeneity, computation of N-Gain scores, and hypothesis testing via the Independent Samples t-test. Results revealed a statistically significant improvement, with a calculated t-value of 4.638 surpassing the critical value of 2.015. The experimental group also recorded a higher mean N-Gain (0.681) than the control group (0.450), confirming that culturally contextualized CTL instruction outperforms conventional teaching methods in building students' statistical literacy.

Keywords: Statistical Literacy, Contextual Teaching and Learning (CTL), Lampung Culture, Data and Diagrams