A study was performed to investigate the shear strength of

A study was performed to investigate the shear strength of soil (y) as it related to depth in feet (x1) and moisture content (x2). Ten observations were collected, and the following summary quantities obtained: n = 10,

(a) Set up the least squares normal equations for the model Y = B0 + B1x1 + B2x2 +.
(b) Estimate the parameters in the model in part (a).
(c) What is the predicted strength when x1 = 18 feet and x2 = 43%?