A = amount in t years
P = initial investment
r = annual interest rate (in decimal form)
t = number of years
n = number of compoundings per year
A = P(1 + r/n)nt
13000 = P(1 + 0.049/4)(4)(4)
13000 = P(1.01225)16
13000 = P(1.215079145)
P = 13000/(1.215079145) = $10,698.89