Answer: The required proportion is
[tex]\dfrac{10}{4}=\dfrac{x}{20}.[/tex]
Step-by-step explanation: Given that the scale on a map shows that 10 kilometers is represented by 4 centimeters.
We are to find the proportion can be used to find the actual distance, x, represented by 20 centimeters on the map.
We have
4 centimeters on the map = 10 kilometers.
So, 1 centimeter on the map [tex]=\dfrac{10}{4}~\textup{kilometers}.[/tex]
Also,
20 centimeters on the map = x kilometers.
So, 1 centimeter on the map [tex]\dfrac{x}{20}~~\textup{kilometers}.[/tex]
Therefore, we must have
[tex]\dfrac{10}{4}=\dfrac{x}{20}.[/tex]
Thus, the required proportion is
[tex]\dfrac{10}{4}=\dfrac{x}{20}.[/tex]
