question: Show the names of customers having an order with shipping method FedEx and order status Paid.
#1 return customers 
#2 return orders of #1 
#3 return statuses of #2 
#4 return shipping methods of #2 
#5 return #1 where #3 is  Paid 
#6 return #1 where #4 is  FedEx 
#7 return #1 in both #5 and #6 
#8 return the  names of #7