Answer :

[tex]4, 12, 6, 18, 9, ...\\\\4\cdot3=12\ \ \ \ \ \ \ \ and\ \ \ \ \ \ \ 12:2=6\\6\cdot3=18\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 18:2=9\\9\cdot3=27\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ 27:2=13.5\ \ \ ...\\\\Ans.\ The\ next\ step\ is\ 27.[/tex]