9.) Sarah & Jim bought a condominium 10 years ago for $210,000. They paid a $10,000 down payment and took out a 30-year mortgage at 5.2% interest compounded monthly to finance the rest. Now interest rates have dropped to 4.8% and they would like to refinance what they still owe with a 20-year mortgage. a) What is Sarah & Jim's current monthly payment, b) What will their new monthly payment be, c) What is the difference between their old monthly payment and their new payment, and d) If all the costs associated with the refinancing are going to total $6,000, is it worth it to refinance, and why? (Hint: compare the $6,000 cost to the present value of all the monthly savings over the next 20 years.) 10.) The Consumer Financial Protection Bureau requires that all lenders make sure that any borrower's monthly debt payments and obligations must not exceed 43% of their pre-tax monthly income. The Martinez family is planning on buying a home, and they have applied for a $301,000 mortgage for 30 years at 4.1% compounded monthly. Their pre-tax income is $60,000 per year. If we assume that the property taxes and the insurance on the home together would be $7,800 year, and the Martinez family have no other debt obligations, then a) What would be their average monthly debt payments and obligations, in dollars, b) What percentage of their monthly pre-tax income is this, and c) Do they qualify for the mortgage