you are $21$ years old today. your grandparents set up a trust fund that will pay

you $$25,000$ per year for $20$ years, starting on your $65$th birthday to

supplement your retirement. if the trust can earn $7\mathrm{.}5\%$ per year, how much

will your grandparents need to put in the trust fund today $($rounded to the

nearest $$10)?$ The answer is $$11,370$ but i didnt quite understand my professor please explain and how to put on on ti$-84$