You are applying for a 30-year, fixed-rate (APR 6.50%), monthly-payment-required mortgage loan for a house that sells for $80,000 today. The mortgage bank will ask you for 20% initial down payment (in cash, paid immediately) of the house value, and charge you an extra $3,000 closing cost (carried into loan balance and amortized later) when the loan is approved. 10 years after buying the house (as Part b aforementioned), the loan market rate drops from 6.50% APR to 4.50% APR, you want to refinance on the remaining loan principal balance, but the bank will charge you an extra $4,000 refinancing fee (carried into the remaining loan balance and amortized later). Would you be able, and by how much, to lower your monthly loan payment if you choose to refinance over the remaining loan life (i.e., instead of the extension of another 30 years)? Based on your calculation results, should you choose to refinance or not?