7) Find the top 5 line items with the largest line_item_amount that belongs to vendor "Federal Express Corporation". Return the vendor name, invoice number and line_item_amount of these 5 items. 8) Select all vendors who have not submitted an invoice. Return a result table that contains the vendor's name and city. Sort by vendor name in descending order. 9) List the vendors and how many invoices that belong to each vendor in descending order. Use proper aliases and return results as below: 10) List all the invoices where the invoice_total is less than the average invoice_total of all invoices. Order by invoice_total in descending order and only return rows where the invoice_total is larger than 800