If m is proportional to n and m = 5 when n = 4, then what is the value of m when n = 18? · ABC26GN2943

$m \propto n \Rightarrow m=kn$ for some constant $k$. When $m=5$ and $n=4$, $m=kn \Rightarrow 5=4k \Rightarrow k=\frac{5}{4}$. When $n=18$, we have: $m=\frac{5}{4}n=\frac{5}{4}\times 18=\frac{45}{2}=22.5$.