Solve for the unknown interest rate in each of the following:

Note: Do not round intermediate calculations and enter your answers as a percent rounded to $2$ decimal places, e$.$g$.,32\mathrm{.}16.$

$\backslash$table$[[$Present Value,Years,Interest Rate,Future Value$],[780,7,\%,1,511],[970,8,\%,1,848],[21,500,19,\%,148,332],[76,800,22,\%,325,815]]$