SFF = (r/n)/{(1+r/n)^nt-1} ------- where SFF = Sinking fund factor, r = Annual interest rate, n= number of payments per year, t = number of years
Substituting,
SFF = (0.06/2)/{(1+0.06/2)^2*2 -1} = 0.239
PMT = A*SFF = 58,000*0.239 = $13,863.57 ---- The closest answer is $13,863.74