Please fix this code, the starting balance is not calculating correctly. When I input $800$ I should get $720$ back as the starting value but it gives $712\mathrm{.}80$ instead. def repayment$\_$plan$($purchase$\_$price$)$:

down$\_$payment$\_$rate $=0\mathrm{.}10$

annual$\_$interest$\_$rate $=0\mathrm{.}12$

monthly$\_$interest$\_$rate $=$ annual$\_$interest$\_$rate $/12$

monthly$\_$payment$\_$rate $=0\mathrm{.}05$

down$\_$payment $=$ purchase$\_$price $*$ down$\_$payment$\_$rate

starting$\_$balance $=$ purchase$\_$price $-$ down$\_$payment

balance $=$ starting$\_$balance

print$("\%4$s $\%18$s $\%16$s $\%16$s $\%14$s $\%20$s$"\%("$Month$",$ "Starting Balance", "Interest Owed", "Principal Owed", "Payment Owed", "Remaining Balance"$))$

for month in range$(1,20)$:

interest $=$ starting$\_$balance $*$ monthly$\_$interest$\_$rate

principal $=$ monthly$\_$payment$\_$rate $*$ purchase$\_$price $-$ interest

payment $=$ purchase$\_$price $*$ monthly$\_$payment$\_$rate

starting$\_$balance $-=$ interest

balance $-=$ payment

print$("\{$:$3$d$\}\{$:$14\mathrm{.}2$f$\}\{$:$16\mathrm{.}2$f$\}\{$:$16\mathrm{.}2$f$\}\{$:$16\mathrm{.}2$f$\}\{$:$16\mathrm{.}2$f$\}".$format$($month$,$ starting$\_$balance, interest, principal, payment, balance$))$

month $+=1$

purchase$\_$price $=$ float$($input$("$Enter the purchase price: $"))$

if purchase$\_$price $>=0$:

repayment$\_$plan$($purchase$\_$price$)$

else:

print$("$End Repayment Plan."$)$