<prompt> Translate the following text to EnglishKwa mfano, ni kudhani kwamba uwiano wa kijijini carrier katika ofisi gharama kwa jumla ya kijijini carrier gharama ni sawa na uwiano wa mji carrier katika ofisi gharama kwa jumla ya mji carrier gharama.  <response>: For example, it is assumed that the ratio of rural carrier in-office cost to total rural carrier cost is the same as the ratio of city carrier in-office cost to total city carrier cost. 