<prompt> Translate the following text to SwahiliWe measure the returns to scale in the U.S. postal delivery function by first determining the total cost of delivery provided by the Postal Service.  <response>: Kwa mfano, kwa ajili ya kipimo cha kiwango cha kurudi kwa kazi ya utoaji wa posta ya Marekani, kwanza tunaamua gharama ya jumla ya utoaji iliyotolewa na Huduma ya Posta. 