Los Angeles is about 385 miles from San Fransico. How far spat would the cities be on a map with a scale of 1in.=mi? Round to the nearest hundredth

Question

mathstudent55 · Answer

What is the scale? Is there a number missing next to mi?

anonymous · Answer

Oh it's supposed to be 1 in. = 25 mi

mathstudent55 · Answer

Ok.
You can do scale problems with a proportion.
If 1 in. equals 25 mi, then how many inches equals 385 mi?
A proportion is two equal ratios.

1 in. is to 25 miles as x inches is to 385 miles.

$\dfrac{1~in.}{25~mi} = \dfrac{x}{385~mi} $

Cross multiply:

$25x = 385\times 1$

$25x = 385$

Divide both sides by 25:

$x = \dfrac{385}{25} $

$x = 15.4 ~in.$