Given the scale is 1 cm to 25 km.
We have to find the length of the trail from centimeter to the nearest tenth of kilometer.
Let's take the length of the trail be x km.
The length of the trail given 7.2 cm. We will have to find the length in km.
We have to set it up as a proportion. So we can write the proportion as,

We have to cross multiply first. We will get,



So we have got the required length of the train in kilometer.
The actual length of the trail = 180km.