The Staff of a Test Kitchen Is Attempting to Determine $y$

Essay

The staff of a test kitchen is attempting to determine the baking time, $y$ , of a roast, i.e., the time it takes the internal temperature of the roast to reach $165^{\circ} \mathrm{F}$ , using two variables, the temperature setting of the oven, $x_{1}$ , and the weight of the roast, $x_{2}$ , in pounds. The data for 24 roasts are shown below.

$\text { Baking Times of Roasts }$


a. $\text { Fit a complete second-order model to the data. }$
b. Do the data provide sufficient evidence to indicate that the second-order terms contribute information for the prediction of $y$ ? State the null and alternative hypothes