I am comfortable working with proportions because I can recognize proportional relationships. I am very comfortable solving proportions to find missing information.
What are proportions?
Proportions are equations that state that two ratios are equivalent. Ratios are comparisons to two quantities, often expressed as a fraction. A proportion typically consists of four quantities, and it can be written in the form
![\[ (a)/(b) = (c)/(d) \]](https://img.qammunity.org/2021/formulas/mathematics/high-school/2nxcg602h358t2r5hifghcw3clylmjjch5.png)
or using colons a:b::c:d
In the given notation "a" and "d" which represent certain values are called the extremes, while "b" and "c" which also denote certain values are called the means. The product of the means is equal to the product of the extremes in a proportion.
I find it comfortable to solve by using any of these three methods which are vertical, horizontal, and diagonal (cross-multiplication). I use vertical method when I see that one of the ratios has a common multiple between the two quantities. I use horizontal method when there is a common multiple between both numerators or denominators. Lastly, I employ the diagonal method, cross-multiplication when any part of the proportion is missing.