CREATE TABLE table_name_59 (erp_w INTEGER, call_sign VARCHAR(255), frequency_mhz VARCHAR(255))
What is the ERP W for the station whose call sign is K248BJ and whose frequency MHz is higher than 97.5?
    
SQL: SELECT AVG(erp_w) FROM table_name_59 WHERE call_sign = "k248bj" AND frequency_mhz > 97.5