The table shows the soil density of several soil samples at different depth 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 20m. Show your work.

Step-by-step explanation:

1). By using quadratic regression calculator,

   Equation of the regression line is,

   y = -0.4931x² + 23.3798x + 996.0289

   Here, y = soil density

   And variable x = depth

2). For soil density of a sample at depth,

   y = -0.4931(20)² + 23.379(20) + 996.0289

   y = -197.24 + 467.58 + 996.0289

   y = 1266.3689

   y ≈ 1266 mg per cm³

answer is 1

step-by-step explanation: