First, you would need to create an equation for this problem. Let x represent the unknown percentage.
[tex] \frac{72}{450} [/tex] = [tex] \frac{x}{100} [/tex]
Next, you would cross multiply.
450x = 7,200
Now, all you would have to do is isolate the x. To do this, you would divide both sides by 450.
x = 16%
You have 16% of the bike's cost.
I hope this helps!