Amount borrowed, P = 13000
Interest, i = 0.07/12 per month
number of periods (months), n = 4*12 = 48
Monthly payment,
[tex]A=\frac{P(i*(1+i)^n)}{(1+i)^n-1}[/tex]
[tex]=\frac{13000(.07/12*(1+.07/12)^{48}}{(1+.07/12)^{48}-1}[/tex]
=311.30 (to the nearest cent)