12. 已知等比数列{an}\{a_{n}\}{an}各项均为正数,3a2+2a3=a43a_{2}+2a_{3}=a_{4}3a2+2a3=a4,{an}\{a_{n}\}{an}的前nnn项和为SnS_{n}Sn,则S3a2=(\frac{{S}_{3}}{{a}_{2}}=(a2S3=( )))