Find the average prices of all products from each manufacture, and list each company's name.
return manufactures ;return products of #1 ;return prices of #2 ;return average of #3 for each #1 ;return companies of #1 ;return names of #5 ;return #4 ,  #6
['select', 'project', 'project', 'group', 'project', 'project', 'union']