P=principal, n=360 months, i=0.067/12 monthly
The equal monthly payments are:
=0.0064527798P
Future value of principal after 29 months
F=P(1+i)^29=P(1+0.067/12)^29=1.1752328813 P
Future value of payments after 29 months
=0.2025204525P
Amount owing after 29 months
=1.1752328813 P - 0.2025204525P
=0.9727124288P
Amount of principal repaid
= P-0.9727124288P
= 0.0272875712P
Portion of payment towards capital (current dollars)
= 0.0272875712P / (29A)
= 0.0272875712/0.1871306136
= 0.14582, or 14.6%