The table shows the soil density of several soil samples at different depths. (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.

9.4.34  question   to estimate the height of a stone  figure, an observer holds a small square up to her eyes and walks backward from the figure. she stops when the bottom of the figure aligns with the bottom edge of the  square, and when the top of the figure aligns with the top edge of the square. her eye level is 1.811.81 m from the ground. she is 3.703.70 m from the figure. what is the height of the figure to the nearest hundredth of a  meter?