The debt is amortized by equal payments made at the end of each payment interval. Compute $($a$)$ the size of the periodic payments; $($b$)$ the outstanding principal at the time indicated; $($c$)$ the interest paid by the payment following the time indicated; and $($d$)$ the principal repaid by the payment following the time indicated for finding the outstanding principal.

Debt princial$=$$$15000$

Repayment period$=8$ years

payment interval$=1$ month

interst rate$=6\%$

conversion period$=$monthly

outstanding principle after$=8$th payment