Chapter 11.4, Problem 12P

(a)

To determine

To test: ${\displaystyle \sum x=193.5},{\displaystyle \sum y=177.2,{\displaystyle \sum x^2=7676.71,{\displaystyle \sum y^2=6432.5}}},$

${\displaystyle \sum xy=7023.19,r\approx \mathrm{0.977.}}$

(b)

To determine

To test: The claim that $\rho >0$ at 0.01 level of significance.

(c)

To determine

To test: $S_e\approx 1.5223,a\approx 1.4084,b\approx 0.8794$

(d)

To determine

To find: The predicted dealer invoice when the list price is 40 (thousand dollars).

(e)

To determine

To find: The 95% confidence interval for $y$ when $x=40$.

(f)

To determine

To test: The claim that $\beta >0$ at 0.01 level of significance.