Answer :
we know that
[tex]25\ grams[/tex] represent a [tex]100\%[/tex] percentage
so
by proportion
[tex]\frac{100}{25} \frac{\%}{grams} =\frac{x}{4} \frac{\%}{grams} \\ \\25*x=4*100\\ \\x=4*100/25\\ \\x=16\%[/tex]
therefore
the answer is
[tex]16\%[/tex]