We are given dimensions of model and actual figure.
model: 9.5cm actual : 30.5m.
We need to find the length of actual shape for the scale factor 5cm.
Let us assume actual length be x m.
Let us set a proportion now.
5 : x = 9.5 : 30.5
Let us convert proportion into fractions.
On cross multiplying, we get
9.5x = 5× 30.5
9.5x = 152.5.
On dividing both sides by 9.5, we get
x=16.05.
Therefore, the scale factor for a model is 5cm= 16.05 m.