Answer: The required proportion is
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
Also,
20 centimeters on the map = x kilometers.
So, 1 centimeter on the map
Therefore, we must have
Thus, the required proportion is