Your parents are purchasing a mobile home for $89,000. The sales tax is 4.2%, they make a $3,000 down payment, and they have an average credit score. How much is the principal balance after applying their first month's payment of $925.67?

The solution would be like this for this specific problem:

89,000*1.042 - 3000 = 89,738

9738 * (.04399/12) = 328.96

925.67 - 328.96 = 596.705

89,738 - 596.705 = 89,141.29

89,141.29 * (.04399/12) = 326.78

So, the principal balance after applying their first month’s payment of $925.67 is 326.78.