The table shows the soil density of several soil samples at different depths. 1
5
6
8
10
12
14
21
23
24
28
Depth (m)
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 = soll density
(b) Use the equation to estimate the soil density of a sample at a depth of 20 m. Show your work.