The resilience y of a certain type of plastic is to be represented as a linear function of both the temperature x1 at which the plastic is baked and the number of minutes x2 for which it is baked. Suppose that 10 pieces of plastic are prepared by using different values of x1 and x2, and the observed values in appropriate units are as given in Table 11.4. Fit a function having the form y = β0 + β1x1 + β2x2 to these observed values by the method of least squares.