Question 1122963
7.2% yearly interest means  {{{7.2/12=0.6}}}{{{percent}}} monthly interest.


18 years at 12 compounding periods per year means {{{18*12=216}}} compounding periods from Dennis's birth to age 18.


p, the initial investment

{{{p*(1.006)^216=9101.31}}}
Solve for p.