Answer:
3.2 cm
Explanation:
If we know that our ratio is 4 cm: 5 km. We can find the unit rate of the scale. Which would be 0.8 cm: 1 km. After we find the unit ratio we can then multiply both sides by 4. (4 * 0.8) : (4*1) After simplifying we get the ratio of 3.2cm: 4 km.