Problem $3$: Calculating Interest Rates. For each of the following, solve for the unknown interest rate:

$\backslash$table$[[,$Present Value $($$$),$Years,Interest Rate,Future Value $($$$),$Points$],[3$ a$,-500\mathrm{.}00,4,?,600\mathrm{.}00,2\mathrm{.}5],[3$ b$,-675\mathrm{.}00,9,?,1,200\mathrm{.}00,2\mathrm{.}5],[3$ c$,-12,500\mathrm{.}00,12,?,85,000\mathrm{.}00,2\mathrm{.}5],[3$ d$,-55,000\mathrm{.}00,24,?,1,200,000\mathrm{.}00,2\mathrm{.}5]]$