This math topic focuses on identifying the explanatory variable in different scatter plots. The problems ask students to determine which variable in each plot explains or affects the other, a foundational concept in understanding correlations within data sets displayed visually. It is a specialized area within introductory data and graph analysis, helping students to discriminate between dependent and independent variables using linear scatter plots. The problems follow a consistent format, asking for the identification of the explanatory variable from two given options. This topic is part of a broader introduction to data and graphs involving scatter plots.