build an ERD for REP $($REP$\_$NUM, LAST$\_$NAME, FIRST$\_$NAME, STREET, CITY, STATE, POSTAL$\_$CODE, COMISSION, RATE$)$

CUSTOMER $($CUSTOMER$\_$NUM, CUSTOMER$\_$NAME, STREET, CITY, STATE, POSTAL$\_$CODE, BALANCE, CREDIT$\_$LIMIT, REP$\_$NUM$)$

ORDERS $($ORDER$\_$NUM, ORDER$\_$DATE, CUSTOMER$\_$NUM$)$

ORDER$\_$LINE $($ORDER$\_$NUM, ITEM$\_$NUM, NUM$\_$ORDERED, QUOTED$\_$PRICE$)$

ITEM $($ITEM$\_$NUM, DESCRIPTION, ON$\_$HAND, CATEGORY, STOREHOUSE, PRICE$)$