Respuesta :
The monthly interest rate is [tex] \frac{12.8}{12} =1.07\%=0.0.0107 [/tex].
The payment rate [tex] P [/tex], monthly interest rate [tex] r [/tex], present value [tex] PV [/tex] and the number of
periods are related as,
[tex] P=\frac{r(PV)}{1-(1+r)^{-n}} [/tex].
Rearranging the above equation,
[tex] P[1-(1+r)^{-n}]=r(PV)\\
P-r(PV)=P(1+r)^{-n}\\
\frac{P-r(PV)}{P}=(1+r)^{-n}\\
n=\frac{\ln (\frac{P}{P-r(PV)} )}{\ln(1+r)}
[/tex]
When [tex] PV=$2200,r=0.0107,P=$152.5 [/tex],
[tex] n=\frac{\ln (\frac{152.5}{152.5-0.0107(2200)} )}{\ln(1+0.0107)}=15.75 [/tex].
Crissy has to make [tex] 16 [/tex] loan payments.
