Peter wants to buy a duplex with a purchase price of $227,000. Peter can afford a 15% down payment. Peter earns $2,500 a month and wants to spend no more than 10% of his income on his mortgage payment. Peter is going to rent out the other half of the duplex. He thinks that if he charges $900 a month in rent this will cover the remainder of his mortgage payment. Given that Peter has a 30 year mortgage with a fixed rate of 6.5%, how should Peter adjust how much he charges for rent of the other half of the duplex?