Chapter 11.2, Problem 45E

(a)

To determine

To construct: a bar graph that comparing the two buyers’ and no-buyers’ and explain.

Explanation of Solution

Given:

  

Calculation:

In every group, the subjects divided by the row total

	Higher	Same	Lower
Buyers	0.5556	0.1944	0.25
Nonbuyers	0.299	0.2577	0.4433

Graph:

  

Buyers think most often that the quality of the products is higher, while nonbuyers think most often that the quality of the products is lower.

(b)

To determine

To find: the test on the basis of given information and about the conclusion.

Explanation of Solution

Given:

Minitab output

  

Calculation:

Using the chi-square test

  $H_0:$ Recycling would not affect efficiency

  $H_1:$ Recycling would affect efficiency

  ${\chi }^2=7.638$

Degree of freedom

  $\begin{array}{l}=\left(3-1\right)\left(2-1\right)\\ =2\times 1\\ =2\end{array}$

P-value = 0.022

Calculation:

Therefore, the P-value is lower than significance level 0.05. So, there should be reject the hypotheses and make the conclusion that Recycling would affect efficiency.