You want to have $$54,546$ in $13$ years. You plan to invest $$7,500$ in $2$ years in investment A$,$ which has an expected return of $6\mathrm{.}48$ percent per year. You also plan to invest $X in $8$ years in investment B$,$ which has an expected return of $12\mathrm{.}84$ percent per year. What is X$?$