Chapter 13, Problem 91CP

a.

To determine

Explain the reason that x plays the role of $x_1$ and $x^2$ the role of $x_2$, in the regression equation ${\mu }_y=\alpha +{\beta }_{1}x+{\beta }_2{x}^2$.

b.

To determine

1. (i) Sketch the prediction equation, $\widehat{y}=10+2x+0.5x^2$ for values of x between 0 and 5.
2. (ii) Sketch the prediction equation, $\widehat{y}=10+2x-0.5x^2$ for values of x between 0 and 5.