You have $$15,000$ in your retirement fund that is earning $5\mathrm{.}5$ percent per year, compounded quarterly. a$.$ How many dollars in withdrawals per month would reduce this nest egg to zero in $20$ years? Use Exhibit $14-7.$ b$.$ How many dollars per month can you withdraw for as long as you live and still leave this nest egg intact? Use Exhibit $14-7.$