A recent graduate's student loans total $13,000. If these loans are at 4.1%, compounded quarterly, for 9 years, what are the quarterly payments

Answer 1

Use
R=quarterly payment
i=interest = 4.1%/4 = 0.041/4
n = 9*4 quarters = 36 quarters
P = principal, present value = $13,000

Then
P(1+i)^n = R((1+i)^n-1)/i
Solve for R, everything else is known.
I get $433.65 (quarterly payment)