We simply divide 48 by 354.
[tex] \frac{48}{354} =0.13559[/tex]
We multiply this then by 100 since we want the percentage (per hundred)
[tex]0.13559*100=13.559[/tex]
Therefore it is 13.559% or 13.56% (depends on your teacher if she wants you to round it) , to stay safe put 13.559%
