#1) Setting up proportions to solve word problems (Take notes on all three (3) examples in your notes.)
https://www.khanacademy.org/math/algebra-basics/core-algebra-linear-equations-inequalities/ratios-core-algebra/v/writing-proportions
#2) Solving a proportion with an unknown variable (Take notes on one example)
https://www.khanacademy.org/math/algebra-basics/core-algebra-linear-equations-inequalities/ratios-core-algebra/v/find-an-unknown-in-a-proportion