<prompt> Translate the following text to EnglishKwa mfano, ikiwa kiasi cha bidhaa katika quintile ya kwanza ingekuwa mara mbili, gharama ya jumla ingekuwa kuongezeka kwa asilimia 29.  <response>: Thus, for example, if the volume in the first quintile were to double, total cost would increase by 29 percent. 