Find the center of mass of a rectangular plate of length 10 cm and width 39 cm. The mass density varies linearly along the length. At one end, it is 8 g/cm2; at the other end, it is 18 g/cm2. (Assume the x-axis begins at the 8 g/cm2 edge and extends along the length. Assume the y-axis extends along the width.)
(??? cm, 19.5 cm)