Answer :
It is given that x is a variable that needs to be found.
By theorem of proportionality:
[tex]\begin{gathered} \frac{PS}{PQ}=\frac{RS}{RQ} \\ \frac{15}{9}=\frac{6}{x} \\ x=\frac{6\times9}{15} \\ x=3.6 \end{gathered}[/tex]Hence the value of x is 3.6