Price of computer = $755.00
Sales tax = 5%
Final price of computer = 755 +

= 755 ×

= $792.75
APR = 17.25 % yearly=8.625%(Semi Annualy)=
% monthly
Total price of computer including APR = 792.75 (1+
)= 792.75 ×
= 792.75 × 1.08625=$861.124
You have to pay this money in six months.
Money paid by me in each month including APRand interest of $ 50 =
+50=$ 193.52
Money paid by me in sixth month, if i miss a payment in the fifth month as an installment of computer= $193.52+$39= $232.52
So,Total Interest charged in sixth month =50+39+APR of each month= 232.52 - 132.125 = $100.395