Answer:
Proportion states that the two ratios or fractions are equal
Given the statement:
The scale on map is 2 cm =25 miles.
Dave measured the distance to the next town at 5 cm.
We have to find the what miles away is the next town.
Let x be the distance in miles away is the next town.
By definition of proportion:

By cross multiply we get;

Simplify:

Divide both sides by 2 we get;
x = 6.25 miles
Therefore, 6.25 miles away is the next town.