How to Solve proportions

This video describes about how to solve multiple proportions. The first step describes how to cross multiply and solve the equation. There are three proportions solved in this video and they are explained how to arrive the final answer. The first step is multiplying the denominator with the opposite numerator and an answer is arrived and again the same is multiplied to arrive a final answer. Two more proportions are solved in the same manner. The video camera is focused on the white board in one position with bright lights focusing the board for clear visibility. Three different colors of marker pencils are used to solve three proportions.