Oil field pipes are internally coated in order to preventcorrosion. Researchers

Oil field pipes are internally coated in order to preventcorrosion. Researchers investigated the influence that coating mayhave on the surface roughness of oil field pipes. A scanning probeinstrument was used to measure the surface roughness of each in asample of 20 sections of coated interior pipe. The data (inmicrometers) are provided in the table below.