Respuesta :
The first proportion:
[tex]6\colon8=n\colon12[/tex]can be written like this:
[tex]\frac{6}{8}=\frac{n}{12}[/tex]then, we have the following:
[tex]\begin{gathered} \frac{6}{8}=\frac{n}{12} \\ \Rightarrow n=(\frac{6}{8})\cdot12=\frac{72}{8}=9 \\ n=9 \end{gathered}[/tex]For the next proportions, we have the following:
[tex]\begin{gathered} \frac{2}{7}=\frac{8}{n} \\ \Rightarrow n=\frac{8}{\frac{2}{7}}=\frac{8\cdot7}{2}=\frac{56}{2}=23 \end{gathered}[/tex][tex]\begin{gathered} \frac{n}{6}=\frac{11}{3} \\ \Rightarrow n=\frac{11}{3}\cdot6=\frac{66}{3}=22 \end{gathered}[/tex]and finally:
[tex]\begin{gathered} \frac{4}{n}=\frac{6}{9} \\ \Rightarrow n=\frac{4}{\frac{6}{9}}=\frac{4\cdot9}{6}=\frac{36}{6}=6 \end{gathered}[/tex]