Answer :

We could write a percent equation. 
What percent of 450 is 28.13?
[tex] \frac{28.13}{450} = \frac{x}{100} [/tex]
Cross multiply and we would get 2813 = 450x
Divide 450 on both sides of the equal sign and x = 6.25111111
Round it
Solution: 6.25% tax