Wisconsin Mathematics Standards
7.RP.A.2 Recognize and represent proportional relationships between quantities.
7.RP.A.2.A Decide whether two quantities are in a proportional relationship, e.g., by testing for equivalent ratios in a table or graphing on a coordinate plane and observing whether the graph is a straight line through the origin.
7.RP.A.2.C Represent proportional relationships by equations.
7.RP.A.3 Use proportional relationships to solve multistep ratio and percent problems
7.EE.B.4 Use variables to represent quantities in a real-world or mathematical problem and construct simple equations and inequalities to solve problems by reasoning about the quantities.