This product has students examine the relationship between the independent variable (x) and dependent variable (y). Students will explore the constant of proportionality (k). The two page worksheet has students calculate the constant of proportionality, write an equation and determine the missing values in the table. The second part of the worksheet asks students to find the missing values in a table if they are provided the constant of proportionality. Students are also asked to explain how they would know if two variables are proportional and how they would know two variables are not proportional in a table. Answer keys are provided.