# Which of the following proportions will allow you to correctly compute the answer to the...

## Question:

Which of the following proportions will allow you to correctly compute the answer to the question: {eq}\; 51 \textrm{ in.} = {/eq} _____ {eq}\textrm{ ft.} {/eq}?

1. {eq}\displaystyle\; \frac{51}{x} = \frac{1}{12} {/eq}

2. {eq}\displaystyle\; \frac{x}{51} = \frac{12}{1} {/eq}

3. {eq}\displaystyle\; \frac{51}{12} = \frac{1}{x} {/eq}

4. {eq}\displaystyle\; \frac{51}{x} = \frac{12}{1} {/eq}

## Foot:

The foot is a unit of length equal to the length of 12 inches based on the Imperial Units and US customary units. In the metric system one foot is equal to 0.3048 meters.

One foot is equal to 12 inches and it is to be determied as to how many feet are there in 51 inches. To determine this, it would be helpful to put the units:

{eq}\rm \dfrac{51 \ inches} { x \ feet} = \dfrac {12 \ inches} {1 \ foot} {/eq}

One can see that the epxressions are proportions of each other based on the units. To solve, cross multiply, and taking note of the units:

{eq}\rm x \ feet = \dfrac{(51 \ inches)(1 \ foot)} {12 \ inches} {/eq}

The unit of inches would be cancelled leaving only feet, such that:

{eq}\rm x \ feet = 4.25 \ feet. {/eq}