Jake buys a house costing $500,000. He puts 20% down and borrows the balance negotiating a 3-year ARM. The initial teaser rate is 3%; after that the interest rate may be adjusted annually to 1% plus the current 90-day T-Bill rate. Annual and lifetime interest rate adjustments and caps are 2% and 6%, respectively. Amortization is done on a 30 year basis. This is a non-carryover ARM.

The 90-day T-bill rate is as follows:

At beginning of year 1:3%

At beginning of year 2:3.5%

At beginning of year 3:4%

At beginning of year 4:4.5%

At beginning of year 5:4.8%

What are Jake's monthly principal and interest payments foryear 4?