2. The table shows the soil density of several soil samples at different depths. Depth (m) 1 5 6 8 10 12 14 21 23 24 28 Soil density (mg/cm) 1045 1063 1102 1140 1191 1232 1249 1254 1265 1268 1273 (a) Write the quadratic regression equation that models the data. Let x = depth below the surface and let y = soil density. (b) Use the equation to estimate the soil density of a sample at a depth of 20 m. Show your work.