Roberts observes: “A house with bare floors and a few area rugs will have about one - tenth of the dust found in a house with wall - to - wall carpet. ”
Roberts menyatakan pengamatannya, ” Kadar debu di rumah yang beberapa bagian lantainya ditutupi permadani hanya sepersepuluh dari kadar debu di rumah yang seluruh lantainya ditutupi karpet. ”