State regulators have approved a request by Appalachian Power to raise its rates to cover its transmission costs. Bills for an average residential customer of Appalachian Power Co. will go up by about $11 per month, effective July 1. The increase was one of several rate adjustments Appalachian Power is asking for this year. The company also is seeking an increase in its base rates, which would increase the bill of a residential customer by about $10 per month. Appalachian Power serves some 500,000 customers in Virginia.