Research and development department of materials and production processes of a university Material was mixed to improve product quality based on material properties test data. Tost whether the modifled material is different or not at 4 = 0.05 material before culty increm mateatter curity mprovement 16.00 162 1675 16.40 17.37 1921 17.12 1835 1600 16.5 1667 1704 1734 10 1702 17,15 17.00 16:59 1727