The check digits enable the sending bank (or its customer) to perform a sanity check of the routing destination and account number from a single string of data at the time of data entry.
Generally, interest rates on FHA-backed mortgages are competitive with conventional mortgages. A quick scan of interest rates for 2012 reveals that FHA mortgages feature rates of about 3.33 percent. The FHA states that the average interest rate for a 30-year fixed loan on a single-family home is about 4.06 percent.
Currently, the average interest rate for a new 30 year fixed-rate loan is 6.3%, and the average FICO credit score is 723. So, if your credit score is better than 720, you should expect to qualify for an interest rate of around 6.3%, or possibly lower.