Chapter 12.5, Problem 46LM

a.

To determine

Find the prediction equation.

b.

To determine

Explain the geometric form of the response surface of Part a.

c.

To determine

Plot the prediction equation for the case when $x_2=1,x_2=3,\text{ and }{x}_2=5$.

d.

To determine

Explain the interactions between $x_1$ and $x_2$.

Explain the reason for the plot in Part c. that suggests an interaction between $x_1$ and $x_2$.

e.

To determine

State the null and alternative hypotheses to test whether $x_1$ and $x_2$ interact.

f.

To determine

Check whether the variables $x_1$ and $x_2$ interacts or not.