Question

What conversion factor is needed to complete the work shown below to convert 253,440 inches to miles?

StartFraction 253,440 inches Over 1 EndFraction times StartFraction 1 foot Over 12 inches EndFraction

The conversion factor needed is
over
.

Answer 1

To convert inches to miles, you will need to know both the number of inches in a foot and the number of feet in a mile. Here are the necessary conversions:

1 foot = 12 inches
1 mile = 5280 feet

To convert from inches directly to miles, you can use these conversion factors.

First, convert inches to feet using the conversion factor \( \frac{1 \text{ foot}}{12 \text{ inches}} \), which you have already shown.

Next, you need to convert feet to miles. The conversion factor for this step is \( \frac{1 \text{ mile}}{5280 \text{ feet}} \).

Putting it all together, the full conversion from inches to miles is:

\[
\frac{253,440 \text{ inches}}{1} \times \frac{1 \text{ foot}}{12 \text{ inches}} \times \frac{1 \text{ mile}}{5280 \text{ feet}}
\]

Therefore, the conversion factor needed to convert inches to miles after you’ve already converted inches to feet is:

\[
\frac{1 \text{ mile}}{5280 \text{ feet}}
\]

So the final answer is:

The conversion factor needed is **1 mile** over **5280 feet**.